Chapter 30 - Esophagus Flashcards
The esophagus of the horse:
● varies between 125 - 200 cm
● varies between 150-225 cm
● consists of dorsal, cervical and abdominal part
● consists of dorsa, thoracic and abdominal part
varies between 125 - 200 cm
As the esophagus courses caudad:
deviates from a position dorsal to the trachea in the cranial third of the neck to the left side of the medial plane in the middle third of the neck
In a small percentage of horses esophagus courses to the right side of the median plane. True?
Yes, esophagus courses to the right side of the median plane
How many layers has the esophagus. Name them.
4 layers, from the outside to the lumen
fibrous layer (tunica adventitia)
muscular layer (tunica muscularis)
submucosal layer (tela submucosa)
mucous membrane ( tunica mucosa)
On surgical incision, the esophageal wall
separates easily into two distinct layers. Name them
The elastic inner layer,
composed of mucosa and submucosa, is freely movable within
the relatively inelastic outer muscular layer and adventitia
The muscular layers of the esophagus are striated from the _______to the base of the heart where they gradually blend into ____________muscle
The muscular layer of the esopahgus are striated from the pharynx to the base of the heart, where they gradually blend into smooth muscle
As the esophagus courses caudad:
● its mucosal layers increase in thickness, whereas the lumen diminishes
● its muscular layers increase in thickness, whereas the lumen increases
● its muscular layers increase in thickness, whereas the lumen diminishes
● its muscular layers increase in thickness, whereas the lumen increases
● its muscular layers increase in thickness, whereas the lumen diminishes
Considering the muscle fiber orientation in the esophagus: At mid-cervical esophagus the bands of muscle form intercrossing__________, in the caudal portion the outer muscle fibers become more ___________oriented, while the inner muscle layer is thicker and more circular
At mid-cervical esophagus the bands of muscle form intercrossing spirals, in the caudal portion the outer muscle fibers become more longitudinally oriented, while the inner muscle layer is thicker and more circular
What is the primary source of arterial supply to the cervical part of the esophagus?
A) Bronchoesophageal arteries
B) Gastric arteries
C) Carotid arteries
D) Mesenteric arteries
C) Carotid arteries
Which arteries supply the thoracic and abdominal esophagus?
B) Bronchoesophageal and gastric arteries
What is the nature of the vascular pattern of the esophagus?
A) Linear and continuous
B) Radial and segmented
C) Arcuate and segmental
D) Circular and unbroken
C) Arcuate and segmental
Why is careful preservation of vessels necessary during esophageal surgery?
C) Because the esophagus lacks generous collateral circulation
Which cranial nerves are involved in the innervation of the esophagus?
A) Eighth and ninth cranial nerves
B) Ninth and tenth cranial nerves
C) Tenth and eleventh cranial nerves
D) Eighth and tenth cranial nerves
B) Ninth and tenth cranial nerves
Besides the cranial nerves, which other structure contributes to the innervation of the esophagus?
A) Parasympathetic ganglia
B) Spinal cord
C) Sympathetic trunk
D) Autonomic plexus
C) Sympathetic trunk
Where are the mesenteric ganglion cells, which contribute to the innervation of the esophagus, located?
A) In the mucosa
B) In the submucosa
C) In the muscularis
D) In the serosa
C) In the muscularis
What symptom often follows attempts at ingestion in a horse with choke?
A) Anorexia
B) Odynophagia (painful swallowing)
C) Weight gain
D) Decreased thirst
B) Odynophagia (painful swallowing)
How soon after swallowing do signs of choke appear with a distal esophagus obstruction?
A) Immediately
B) 1-2 seconds
C) 10-12 seconds
D) 20-25 seconds
C) 10-12 seconds
What is the propagation speed of the equine esophagus in the proximal two-thirds?
A) 2.3 cm/second
B) 4.6 cm/second
C) 7.1 cm/second
D) 9.4 cm/second
D) 9.4 cm/second
Which condition often accompanies long-duration choke cases?
A) Hypertension
B) Hyperactivity
C) Electrolyte imbalances
D) Weight gain
C) Electrolyte imbalances
What complication frequently follows esophageal obstruction in horses?
B) Aspiration pneumonia
What is recommended during the physical examination of a horse with signs of choke to rule out rabies?
A) Immediate sedation
B) Wearing gloves
C) Administering antibiotics
D) Isolating the animal
B) Wearing gloves
What may be indicated by crepitation of a diffuse, firm enlargement in the cervical esophagus?
Loss of integrity of the esophageal wall
What diagnostic procedure can confirm luminal obstruction in a horse with choke?
Passage of a nasogastric tube
What medication is used to sedate a horse with choke during treatment to prevent further aspiration?
Sedation of the animal with xylazine (1.1 mg/kg IV) lowers the horse’s head and prevents further aspiration
What procedure is recommended to relieve an esophageal obstruction caused by feed or bedding?
Gentle lavage with warm water through a nasogastric tube
What should be monitored in any esophageal disease to check for the development of aspiration pneumonia?
Auscultation and diagnostic imaging of the thorax
What is the main advantage of ultrasonographic examination of the cervical esophagus?
It aids in the determination of the etiology of the obstruction.
What can be identified using ultrasonographic examination besides simple impactions?
Extramural masses
What is the purpose of using barium paste (85% wt/vol with water, 120 ml) in an esophagram?
To outline the longitudinal mucosal folds of the undistended esophagus
Why should the patient preferably not be sedated during the administration of barium for an esophagram?
Sedation suppresses the swallowing reflex and reduces the amount of barium available to coat the esophagus.
What does the administration of liquid barium (480 ml) followed by air (480 ml) achieve in esophagographic studies?
It provides a double-contrast study, permitting examination of mucosal folds with the esophagus distended.
Why is negative-contrast radiography less informative for the caudal cervical and thoracic portions of the esophagus?
Because of the superimposition of the air density of the trachea and lungs.
How can negative contrast radiography be used?
In the cranial cervical area, where the esophagus lies dorsal to the trachea, lesions that restrict distention of the esophageal lumen can be demonstrated with negative-contrast radiography - flexible endoscope can be used to localize the lesion and to insufflate the esophagus during radiography. Alternatively, air (480 mL) delivered by dose syringe under pressure through a cuffed nasogastric tube achieves the same results
What complication can arise from the act of swallowing during contrast studies of the esophagus?
False signs of esophageal stricture
How can you avoid false signs of esophageal stricture?
By administering xylazine (1.1 mg/kg iV) 5 minutes before the procedure
Negative radiographic contrast is obtained with
Flexible endoscopy
What potential false diagnostic sign can detomidine induce during an esophagogram, and for how long can it persist?
False signs of megaesophagus; for more than 30 minutes
What additional role does esophagoscopy play when radiographic findings are not diagnostic?
It can define the severity and extent of esophageal lesions.
What feature of the endoscope is necessary for good observation of mucosal lesions?
Flexible with irrigation and insufflation capabilities
Why is endoscopic examination best performed with the endoscope fully inserted and then slowly withdrawn?
To make diagnostic observations while insufflating the esophageal lumen
Red discolorations in mucosa are indicative of
Mucosal disease
Why might the cranial aspect of the cervical esophageal sphincter be difficult to examine endoscopically?
The swallowing reflex is repeatedly stimulated, directing the endoscope tip dorsad.
What endoscopic finding usually indicates disease when observing the esophagus?
Inability to insufflate the esophagus and flatten the mucosal folds
What can produce transverse folds in the esophagus during endoscopy?
Moving the endoscope tip toward the stomach
Why saliva might need to be removed with NG tube help?
To allow clearer observation of the area of concern
What is the normal appearance of the esophageal mucosa on endoscopic examination?
White to light pink
How can the outline of the trachea be observed during esophagoscopy?
By observing the cervical esophagus when insufflated
What is a key diagnostic feature of the cervical esophagus during endoscopy?
Absence of longitudinal mucosal folds
What should be done if the endoscopic appearance of an esophageal obstruction is obscured by saliva?
Remove the saliva by suction through a nasogastric tube
What diagnostic method is routinely used to evaluate esophageal dysfunction in humans?
C) Intraluminal pressure manometry
What have manometric techniques in horses helped to establish?
Reference esophageal pressure profiles
How many functionally distinct regions of the equine esophagus are identified through manometry?
Four
Which region of the equine esophagus is described as “fast”?
Cranial two-thirds of the esophageal body
Which region of the equine esophagus is described as “slow”?
Caudal one-third of the esophageal body
What type of disorders can manometry better define in horses when conventional methods fail?
Physiologic disorders of the esophagus
What specific clinical information has manometry provided regarding esophageal function in horses?
The effect of drugs used to treat esophageal obstruction
The effect of drugs used to treat esophageal obstruction
A) Upper esophageal sphincter, middle esophagus, lower esophageal sphincter, and gastric junction
B) Cranial esophageal sphincter, caudal esophageal sphincter, “fast” region, and “slow” region
C) Cervical esophagus, thoracic esophagus, abdominal esophagus, and esophageal junction
D) Anterior esophagus, posterior esophagus, lateral esophagus, and medial esophagus
B) Cranial esophageal sphincter, caudal esophageal sphincter, “fast” region, and “slow” region
Manometry allows to
It provides a more detailed assessment of esophageal pressure profiles.
Which surgical approach is ideal for esophagotomy and resections involving the proximal third of the cervical esophagus?
A) Ventral approach
B) Ventrolateral approach
C) Thoracotomy
D) Ventral cervical approach
d) Ventral cervical approach
For placing a feeding tube in the mid-cervical esophagus, which approach is recommended?
A) Ventral cervical approach
B) Ventral approach
C) Ventral or ventrolateral approach
D) Thoracotomy
C) Ventral or ventrolateral approach
Which approach is necessary to access the distal half of the esophagus?
A) Ventral cervical approach
B) Ventrolateral approach
C) Thoracotomy
D) Dorsal approach
C) Thoracotomy
What is the purpose of passing a nasogastric tube before inducing anesthesia for esophageal surgery?
To facilitate identification of the esophagus during surgery
What is the purpose of passing a nasogastric tube before inducing anesthesia for esophageal surgery?
A) Infection
B) Laryngeal hemiplegia
C) Esophageal stricture
D) Tracheal collapse
B) Laryngeal hemiplegia
During the ventral approach, which muscles are separated along the midline to expose the trachea?
A) Sternocleidomastoid and omohyoid
B) Sternohyoid and sternothyroid
C) Sternothyroid, sternohyoid, and omohyoid
D) Omohyoid and platysma
C) Sternothyroid, sternohyoid, and omohyoid
What advantage does the ventral approach offer in equine esophageal surgery?
A) Shorter recovery time
B) Excellent ventral drainage
C) Easier access to the thoracic esophagus
D) Minimal muscle separation
B) Excellent ventral drainage
Which approach is used to facilitate firm anchorage of a feeding tube to the skin and prevent impingement on the trachea?
A) Ventral cervical approach
B) Ventral approach
C) Ventrolateral approach
D) Thoracotomy
C) Ventrolateral approach
During the ventrolateral approach, which muscle may need to be incised in the caudal cervical area?
A) Omohyoid muscle
B) Sternothyroid muscle
C) Sternohyoid muscle
D) Cutaneous colli muscle
D) Cutaneous colli muscle
What position is the horse placed in for a thoracotomy to approach the thoracic esophagus?
A) Dorsal recumbency
B) Left lateral recumbency
C) Right lateral recumbency
D) Ventral recumbency
C) Right lateral recumbency
For an intrathoracic esophageal stricture, through which intercostal space was the esophagomyotomy performed on a 5-month-old foal?
A) Fourth intercostal space
B) Fifth intercostal space
C) Sixth intercostal space
D) Eighth intercostal space
D) Eighth intercostal space
In the case of an intrathoracic esophageal pulsion diverticulum in a 7-month-old foal, which rib was resected?
A) Fourth rib on the left side
B) Fifth rib on the right side
C) Eighth rib on the left side
D) Ninth rib on the right side
C) Eighth rib on the left side
Which structures must be sharply divided during the approach to the thoracic esophagus?
A) Sternothyroid and sternohyoid muscles
B) Omohyoid and platysma muscles
C) Serratus ventralis and latissimus dorsi muscles
D) Sternocleidomastoid and omohyoid muscles
C) Serratus ventralis and latissimus dorsi muscles
Why might a subperiosteal rib resection not be necessary in foals during thoracic esophageal surgery?
A) Because the ribs are more flexible
B) Due to the smaller size of the esophagus
C) Rib retractors may provide adequate exposure
D) Foals have thinner muscles
C) Rib retractors may provide adequate exposure
What dictates the choice of intercostal space for a thoracotomy to approach the distal half of the esophagus?
B) Location of the lesion and surgical plan
What procedure was performed on a 7-month-old foal to resect an intrathoracic esophageal pulsion diverticulum?
C) Resection of the eighth rib on the left side
What is essential in anestesia to have during the surgical approach to the thoracic esophagus?
B) Positive-pressure ventilation
In foals, what may not be necessary due to adequate exposure provided by rib retractors during thoracic esophageal surgery?
A) Subperiosteal rib resection
B) Division of the latissimus dorsi muscle
C) Positive-pressure ventilation
D) Incision of the cutaneous trunci muscle
A) Subperiosteal rib resection
What is the most common type of obstructive esophageal disease in animals?
A) Perforation by a foreign body
B) Stricture due to mucosal ulceration
C) Impaction with ingesta or bedding
D) Esophageal tumor
C) Impaction with ingesta or bedding
Which treatment method is usually successful in relieving esophageal obstruction?
C) Nasogastric tube passage and gentle warm water lavage
Which drug is noted for its effect on esophageal relaxation in horses?
A) Acepromazine
B) Diazepam
C) Atropine
D) Lidocaine
A) Acepromazine
In refractory cases of esophageal impaction, which procedure may be necessary if gentle lavage is unsuccessful?
C) Muzzling the animal and repeating treatment after 8 to 12 hours
What is a potential complication of simple impaction of the esophagus that may predispose to reobstruction?
B) Fusiform dilation of the esophagus
For how many days is broad-spectrum antimicrobial therapy generally indicated due to the high risk of aspiration pneumonia following choke?
C) 5 to 7 days
What diagnostic tools are mentioned for identifying foreign bodies in the esophagus?
A) MRI and CT scan
B) Blood tests and biopsy
C) Radiography, ultrasonography, and esophagoscopy
D) Endoscopy and biopsy
C) Radiography, ultrasonography, and esophagoscopy
Figure 30-5. Complete obstruction of the esophagus is localized on esophagography after barium paste swallow. This adult horse had an esophageal stricture. Note the prestenotic dilation.
Figure 30-4. Barium paste (120 mL) given orally outlines the normal longitudinal folds of the mucosa in the undistended lumen of the esophagus.
Figure 30-6. Positive-contrast esophagogram (using liquid barium administered under pressure through a nasogastric tube fitted with an inflatable cuff) shows the distended lumen of the normal esophagus. The cuff prevents reflux of barium into the pharynx and aspiration into the trachea.
How do you administer liquid barium?
Liquid barium (72% wt/vol with water, 480 mL) can be administered under pressure by a dose syringe through a cuffed nasogastric tube to prevent reflux into the pharynx (Figure 30-6). 480 mL of LB followed by air 480 mL
Liquid barium : name the four things that allows to ID
- strictures and associated prestenotic dilation of the esophagus,
- masses that displace the esophagus
- best definition of mucosal lesions - mucosal ulcers after feed impaction
- Rupture of the esophagus with barium escapind to surrounding soft tissues
How many type of esophagography can be performed?
1.Feeding the horse with barium past (85%wt/vol with water 120 mL) given by mouth = longitudinal mucosal folds of the undistended esopagus = localization of obstruction or any disruption
2. Cuffed nasogastric tube and liquid barium (82% wt/vol with water 480mL) = strictures and prestenotic dilation as masses
3. Double contrast esophagogram (using liquid barium 480 mL followd by bolus of air 480 mL) delivered by dose dyringe under pressure = mucosal folds with the esophagus distended = better for mucosal lesions such as ulcers
Although a diagnosis can often be made without using all three techniques, each demonstrates lesions not seen with the
other two.
Figure 30-9. Barium esophagogram shows false signs of a stricture when barium is administered under pressure and the radiograph is made during swallowing. This swallow artifact can be avoided if xylazine is administered 5 minutes before the study is begun.
Figure 30-8. Negative-contrast esophagogram (using air insufflation introduced through the flexible endoscope) permits visual localization of the lesion with the endoscope and demonstrates a stricture.
The act of swallowing during contrast studies, when the lumen is being distended, produces false signs of esophageal stricture (Figure 30-9) - how can you contourn?
Xylazine (1.1 mg/kg IV) 5 minutes before the barium-under-pressure, double-contrast, or negative-contrast esophagogram, helps eliminate this swallow artifact by decreasing the reflex “secondary swallows”
Why you shouldn’t use detomidine (use xylazine) before the esophagogram?
if detomidine is used, false signs of megaesophagus can persist for more than 30 minutes.
Is the cranial aspect of the cervical esophageal sphincter easily visible?
No, it is difficult to examine because the swallowing reflex is stimulated repeatedly and the larynx directs the endoscope tip dorsad.
What are the 3 surgical approaches to equine esophagus that can be used?
- Ventral cervical approach
- Ventral or ventrolateral approach
- Thoracotomy
Ventral cervical approach is to which situation?
The ventral cervical approach is best used for esophagotomy, esophagomyotomy, and resections involving the proximal third of the cervical esophagus
The ventral or ventrolateral approach is used in which situation?
ventral or ventrolateral approach is recommended for placing a feeding tube in the mid-cervical esophagus (esophagostomy) or for approaching the distal quarter of the cervical esophagus, especially near the thoracic inlet
In which situation do you do thoracotomy?
Thoracotomy is necessary to approach the distal half of the esophagus; the choice of intercostal space is dictated by the surgical plan and location of the lesion
Which nerve can be easily traumatized during esophagic surgery?
recurrent laryngeal nerve and vagosympathetic trunk, which are easily traumatized when retracting the carotid artery away from the esophagus
Ventral approach is standing or under GA?
both, standing or under general anesthesia in dorsal recumbency
How do you perform a ventral approach?
A 10-cm skin incision permits exposure of about **6 cm of the esophagus*£. The skin and subcutaneous fascia are divided sharply. The paired sternothyroid, sternohyoid, and omohyoid muscles are separated along the midline to expose the trachea (Figure 30-14). Blunt separation of fascia along the left side of the trachea permits identification of the esophagus containing the nasogastric tube. Retraction of the trachea to the right of the median plane and gentle dissection of overlying loose adventitia expose the ventral wall of the esophagus.
Figure 30-14. (A) A 10-cm (4-in) incision through the skin and subcutaneous fascia, which is sharply divided using the scalpel. (B) The paired muscles of the sternothyroid, sternohyoid, and omohyoid are separated along the midline to expose the trachea. (C) A baby Balfour retractor placed through the incision allows easy access to the esophagus.
What is the advantage of ventral approach?
This approach has the advantage of allowing for excellent ventral drainage should the need arise
Figure 30-15. Placement of a feeding tube ventral to the jugular vein permits it to lie in a comfortable position on the neck. Note the butterfly tape bandage sutured to the skin to firmly anchor the tube, along with saliva loss around the tube
Ventrolateral approach affords good access to which structures?
good access to the middle and distal cervical esophagus, where the ventral cervical musculature becomes more heavily developed, making the ventral approach more difficult. This surgical approach may be performed with the horse standing using local anesthesia, or with the horse in dorsal or right lateral recumbency under general
anesthesia
Ventrolateral approach - describe the procedure
A 5-cm skin incision (for feeding tube placement) is made just ventral to the jugular vein. The sternocephalicus and brachiocephalicus muscles are separated, and the deep cervical fascia is incised to expose the esophagus. It may be necessary to incise the cutaneous colli muscle in the caudal cervical area.
Thoracic esophagus approach can be used in which anomalieS?
An approach to the thoracic esophagus can be used for vascular ring anomalies or when the suspected lesion can be resolved surgically without entering the esophageal lumen.
Describe the thoracic esophagus approach
The patient is placed in right lateral recumbency under general anesthesia. Positive-pressure ventilation is essential. The skin, subcutaneous tissue, cutaneous trunci, serratus ventralis, and latissimus dorsi muscles are sharply divided. A subperiosteal rib resection has been described. This may not be necessary in foals, because rib retractors may provide adequate exposure
What is the most common type of osbstructive esophageal disease?
Impaction with ingesta or bleeding esophagus with typical radiographic appearance (Figure 30-16)
In case of esophagic obstruction you can administer certain meds, name them with dosage
Oxytocin administered intravenously (at 0.11 and 0.2 I iU/kg) resulted in significant short-term relaxation of esophageal musculature in experiments, and is frequently used as an adjunctive treatment for esophageal impaction. Because xylazine 1.1 mg/kg has similar effects, these drugs can be used together to reduce the tone of the esophageal musculature, allowing passage of the obstruction with reduced risk of esophageal injury. Another option to promote muscle relaxation is N-butylscopolammonium bromide (0.3 mg/kg IV), an anticholinergic muscarinic antagonist often used as an analgesic agent that has shown potential efficacy for spasmodic abdominal pain. This drug generally works on smooth muscle, so it may be more efficacious for distal esophageal obstructions.
In case of horses refractory to medical treatment such as NG lavage, IV medication what other tx can you use?
Refractory cases or intractable horses may benefit from general anesthesia and lavage under pressure
Advantages and disadvantages of lavage under pressure and GA
advantages of providing some relaxation of the esophageal musculature, reducing the chances of aspiration (because the horse’s head is lowered), and decreasing the risk of esophageal perforation with the tube in a difficult horse.
disadvantage gentle manipulation is mandatory with this technique to avoid rupture of the esophagus.
Figure 30-17. Lateral cervical radiograph of a horse after impaction of the esophagus has been relieved shows a fluid line in an area of dilation that extends from the distal point of the obstruction proximad to the upper esophageal sphincter. The fluid line is produced by saliva that has collected in the dilated area.
Fusiform dilation is a potential complication of simple impaction of the esophagus that may predispose to reobstruction. What is the tx?
This condition usually resolves in 24 to 48 hours, provided the dilation is kept free of ingesta. Food should be withheld or only small quantities of a soft diet fed for 2 days after an episode of choke to permit the lumen to resume its normal diameter. In addition to fresh water, glucose-electrolyte solutions are provided for drinking to compensate for energy deficiency and electrolyte abnormalities secondary to salivary loss
What is a recommended method for treating longitudinal mucosal ulcers and preventing esophageal stricture formation?
A low-bulk, minimally abrasive diet (mash), nonsteroidal antiinflammatory drugs (NSAIDs, only if they are not implicated as causative agents), and broad-spectrum antimicrobial therapy are indicated
N-butylscopolammonium bromide dosage, molecule?
N-butylscopolammonium bromide (0.3 mg/kg IV), an anticho-linergic muscarinic antagonist often used as an analgesic agent that has shown potential efficacy for spasmodic abdominal pain.
In which timeframe is secure closure of a ruptured or perforated esophagus typically possible?
Within 12 hours after the perforation
Which medication is mentioned as an anticholinergic muscarinic antagonist used for esophageal obstruction?
N-butylscopolammonium bromide
What is a primary concern when using a nasogastric tube to relieve an esophageal impaction?
The potential for esophageal rupture
What should be done if during esophagotomy is performed in a region of the esophagus that appears normal?
Close the mucosa with simple-continuous suture
When dealing with long-standing esophageal impactions, what is recommended for reexamination frequency?
Every 10 to 14 days
What is a potential result of repeated or aggressive nasogastric tube passage in the esophagus?
Rupture or perforation of the esophagus
In case of foreign body if the endoscopy is too difficult to find the issue, how should you approach?
Under GA (avoid deglutition reflex) do a Longitudinal esophagotomy with primary closure results in minimal complications when performed in a region of normal esophagus and is an accepted method of removing a foreign body.Alternatively, the esophagotomy can be left open to heal by second intention. If you use a nasogast tube to push the object there is a risk of moving the foreign body from the cervical region only to have it lodge in the thorax, a less accessible site
Describe esophagotomy technique under GA
GA DR and ventral surface of the neck is aseptic prep
10-cm skin incision is made and the esophagus approached
Care should be taken to preserve the small blood vessels that supply the esophagus. Elevation of the esophagus from its bed of adventitia should be avoided. The left carotid sheath, containing the carotid artery and vagus and recurrent laryngeal nerves, should be gently retracted laterally. Pediatric-size Balfour abdominal retractors aid exposure of the esophagus, which then can be sharply incised through the adventitia, muscularis, submucosa, and mucosa cranial to, caudal to, or directly over the foreign body (Fig 30-19)
Figure 30-19. (A) Longitudinal skin incision exposes the carotid artery (left), esophagus (center), and trachea (right). (B) In this longitudinal esophagotomy, a scalpel is used to incise both the outer layer (muscularis and adventitia) and the inner layer (mucosa and submucosa). (C) The esophagotomy is closed with simple-continuous sutures in the inner layer (mucosa and submucosa) and simple-interrupted sutures in the outer layer (muscularis and adventitia).
How do you close the incision in case of esophagotomy?
After removal of the foreign body, if the esophagus has a normal appearance in the area of the incision, mucosal closure should be completed using a simple-continuous suture of 3-0 monofilament absorbable suture material. Some surgeons advocate having the suture knots tied in the lumen (see Figure 30-19). Esophageal musculature may be apposed with simple-interrupted sutures of 3-0 absorbable suture material. Muscular layers, subcutaneous tissue, and skin are apposed routinely. A polyethylene drain is placed beside the esophagus and exited ventral to the skin incision through a small stab wound. This drain is maintained under constant suction for 48 hours to remove serum and blood
Why you should place a drain for the next 48 of esophagotomy?
This drain is maintained under constant suction for 48 hours to remove serum and blood from the surgical site and to provide early detection of salivary leakage should dehiscence occur.
What is the postop care of an esofagotomy?
Postoperatively, feed should be withheld for 48 hours. Parenteral administration of electrolyte solution, the composition of which depends on the horse’s acid-base, electrolyte, and hydration status, may be used to maintain hydration. Small quantities of pelleted feed in a slurry should be fed over the next 8 days before normal feeding can be resumed. Most esophagotomy incisions heal by first intention, and the intraluminal suture will slough into the lumen within 60 days
Figure 30-20. Endoscopic appearance of a longitudinal esophagotomy that healed by first intention 48 days after surgery. One loop of the suture remains in the healed esophagotomy site.
Beside long standing impactions what other causes can be present for esophageal ulceration in foals?
phenylbutazone toxicity, in which generalized gastrointestinal mucosal disease is a feature, and severe gastroduodenal ulcer disease that produces secondary reflux esophagitis.
What is the treatment for mucosal ulceration
Minimally abrasive died
NSAID
Broad spectrum AB
Muzzle the patint and remove all beffing
Reexam 10-14 dyas
Stricture may occur 30 day after insult if the ulcer is longer than what size?
2.5 cm
Longitudinal mucosal ulcers (especially if they are not extensive and localized to one area of the esophagus) and circumferential ulcers less than 2 cm long usually heal without stricture formation.
Reasons for esophagus rupture (name 3)
- secondary to long-standing obstruction,
- repeated or aggressive nasogastric tube passage, foreign body perforation,
- external trauma to the cervical area (usually a kick), or extension of infection from surrounding strictures
Figure 30-18. Lateral cervical radiograph of horse with esophageal rupture. Note the extensive subcutaneous emphysema.
How can you diagnose esophageal rupture
Swallowed air escapes from the rupture and causes subcutaneous emphysema; this can be recognized ultrasonographically or radiographically (see Figure 30-18). Positive-contrast techniques demonstrate escape of barium into surrounding tissues
(Figure 30-22).
Figure 30-22. Barium swallow in a horse with a penetrating foreign body (wire) shows swallowed air and barium that has escaped into the periesophageal tissue.
Figure 30-23. (A) Establishment of ventral drainage following esophageal rupture, in which multiple incisions needed to be made to drain food material from the cranial pectoral area.
Figure 30-25. Slurry made of complete pelleted feed is used to meet the nutritional needs of the patient. In some cases, the feeding tube can be placed through the site of rupture into the stomach
Conservative tx of rupture esophagus after 12 hours when closure is not advised?
receive systemic antibiotics and water; electrolyte and nutritional requirements should be met by tube feeding or parenteral nutrition. In some cases, the feeding tube can be placed through the site of rupture into the stomach. An alternative method of feeding, allowing spontaneous healing of the rupture or successful repair of the rupture when edema and infection have been controlled, is an esophagostomy performed aboral to the rupture. The tube should be secured firmly, first with butterfly tape bandages sutured to the skin (
esophagostomy should be placed aboral or boral to the area of esophageal injury ?
aboral = distant from the mouth or injury
Describe the ventral approach for esophagostomy
a 6-cm incision is made on the ventral midline at the level of the fifth cervical vertebrae, through the cutaneous colli muscle and between the paired sternocephalicus muscles. he trachea and sternothyroid muscles will be evident. The esophagus is located and using a combination of gentle blunt and sharp dissection of the fascia, isolated, and drawn toward the skin incision. Swallowing and coughing can be decreased by spraying the area with lidocaine. A small, 1-cm incision is made through the esophageal adventitia and muscularis layers, and then spliced with Allis tissue forceps. The mucosa is grasped and everted between the cut edges of the muscle before a transverse incision is made through half the width of the everted mucosa. The nasogastric tube is removed, and a polyethylene nasogastric tube (with an outer diameter of 14–24 mm) is placed into the stomach through the esophagostomy. The tube should be secured firmly, first with butterfly tape bandages sutured to the skin
Describe the ventrolateral approach for esophagostomy
6-cm skin incision is made ventral to the jugular vein (usually on the left side but occasionally the esophagus is on the right). The trachea and sternothyroid muscles will be evident. The esophagus is located and using a combination of gentle blunt and sharp dissection of the fascia, isolated, and drawn toward the skin incision. Swallowing and coughing can be decreased by spraying the area with lidocaine. A small, 1-cm incision is made through the esophageal adventitia and muscularis layers, and then spliced with Allis tissue forceps. The mucosa is grasped and **everted+* between the cut edges of the muscle before a transverse incision is made through half the width of the everted mucosa. The nasogastric tube is removed, and a polyethylene nasogastric tube (with an outer diameter of 14–24 mm) is placed into the stomach through the esophagostomy.
For how long should the esophagostomy tube should remain?
Esophagostomy tubes should remain in place for a minimum of 7 to 10 days to permit granulation tissue to form a true stoma (Figure 30-26).
Figure 30-26. An esophagostomy tube should remain in place for a minimum of 7 to 10 days to permit granulation tissue to form a true stoma.
Stricture can be classified into 3 types according to the anatomic location name them
Type I mural lesions that involve only adventitia and muscularis
Type II esophageal rings or webs that involve only the mucosa and submucosa
Type III annular stenosis that involves all layers of the esophageal wall
Strictures are best shown with which type of esophagogram?
Positive-pressure contrast esophagogram (Figure 30-29)
Figure 30-29. Positive-pressure esophagogram showing a stricture in a foal. Note the prestenotic dilation. The lesion was resolved by partial resection and anastomosis
Conservative management of a stricture is aimed at
dilation of the stenotic segment
When is the conservative tx not advised in strictures?
Strictures more than 60 days old have usually matured to the point where the cicatrix is too firm to yield any conservative therapy and therefore may be classified as chronic (Figure 30-31).
Figure 30-31. Positive-contrast esophagogram using liquid barium administered under pressure through a cuffed nasogastric tube shows stricture with prestenotic dilation. The stenosis was subsequently resolved by esophagomyotomy - Strictures more than 60 days old have usually matured to the point where the cicatrix is too firm to yield any conservative therapy and therefore may be classified as chronic
Figure 30-30. Endoscopic appearance of a stricture 30 days after circumferential ulceration.
Conservative management of stricture
Conservative management of stricture is aimed with dilation of the stenotic segment. Postsurgical strictures or those following circumferential ulceration can be dilated with the frequent feeding of small quantities of soft food over a period of several
months + AB + AINS and delay 60 because it can return to NORMAL
Chronic strictures of the esophagus may be corrected by surgical intervention, name the surgical procedures
- esophagomyotomy,
- partial or complete resection and anastomosis,
- creation of a traction diverticulum,
- or patch grafting
Esophagomyotomy is performed how?
The outer, strictured layers of the esophagus are incised longitudinally to the level of the submucosa or mucosa, through the stricture, and 1 cm distal and proximal to it. Elevation and separation of the outer (muscularis and adventitia) and inner (mucosa and submucosa) layers of the esophageal wall to complete the esophagomyotomy. (C) The muscularis and adventitia are not sutured. The mucosa if inadvertently open it should be immediately closed with 3-0 monof suture
Figure 30-32. (A) Esophagomyotomy: longitudinal incision of the outer layer of the esophageal wall.
(B) Elevation and separation of the outer (muscularis and adventitia) and inner (mucosa and submucosa) layers of the esophageal wall to complete the esophagomyotomy. (C) The muscularis and adventitia are not sutured.
In the esophagotomy Is the the myotomy sutured?
The myotomy is not sutured (FIG 30-32 C) muscularis and adventícia left open
What is a potential issue that can occur weeks or months after an esophagomyotomy?
Rapid development of postsurgical cicatricial stricture.
What may a postsurgical stricture observed long after the original operation indicate?
A mature, nonresilient cicatrix.
When is it recommended to perform another esophagomyotomy in cases of restricture?
Only after acute inflammation from the previous surgery has subsided.
What should be expected after resection and patch grafting?
Leakage of luminal contents and reformation of the stricture requiring prolonged medical management are to be expected after resection and patch grafting. Strictures that are mural in origin respond to myotomy and have the best prognosis for recovery without restricture
What may be necessary if conservative treatment fails to resolve a recurrent obstruction?
Another esophagomyotomy or a more invasive procedure.
What happens to the muscularis during an esophagomyotomy?
It is separated from the mucosa by sharp dissection around the entire circumference of the esophagus. Left open the longitudinal incision
What characterizes a postsurgical stricture that may not respond to dilation?
A mature, nonresilient cicatrix.
What is the role of the nasogastric tube during an esophagomyotomy?
To assist in identifying the stenotic area.
Which surgical step in myotomy is rarely necessary when the mucosa is freed correctly?
Removal of a portion of the muscularis or making multiple myotomy incisions.
What postoperative sign indicates that normal feeding may be resumed?
Radiographic evidence that prestenotic dilation is no longer evident.
If during esophagomyotomy the mucosa is opened inadvertently what should you do?
The mucosa should be closed immediately with 3-0 absorbable monofilament sutures in a simple-continuous pattern
When the cicatrix involves the mucosa and prevents passage of NG tube after myotomy what should you do?
Partial resection where a longitudinal esophagomyotomy combined with mucosal resection provides relief of stricture caused by esoahgeal rings or webs or annular stenosis of all muscle layers
Figure 30-34. Partial resection and anastomosis. After longitudinal incision of the outer layer (A), the inner layer is resected (B), and when possible, closed transversely using several simple-continuous sutures (C). The outer layer is then closed with interrupted sutures (D).
Describe the partial resection
The esophagus is exposed and incised as described previously for esophagomyotomy. A longitudinal incision is made through the mucosa, long enough to permit identification of the diseased segment (Figure 30-34, A). The mucosal scar is separated by sharp dissection from the normal or diseased muscle layer. Circumferential incisions are made at the proximal and distal edges of the mucosal cicatrix and it is removed, leaving the muscular tube intact (see Figure 30-34, B).
If cut edges of the mucosa can be brought into apposition without undue tension, they are apposed by equally spaced absorbable simple-continuous sutures. Some prefer to have the knots tied in the lumen (see Figure 30-34, C).
When mucosal rings or webs are the cause of stenosis, the normal esophageal muscle should be
be apposed over the mucosal anastomosis Figure 30-34, D), but in the case of an annular stenosis that involves the entire esophageal wall, the muscularis should not be sutured.
What is the management postop of partial resection
A drain is placed next to the esophagus and the approach incision is closed. If space permits, tube feeding through a separate, more aborally located esophagostomy is ideal. When this is not possible, frequent feeding of small quantities of soft food may begin 48 hours after surgery and should be continued for 10 days before normal roughage is offered to the patient.
Resection and Anastomosis is reserved to which situations?
rupture of the esophagus in the presence of nonviable muscularis
Describe resection and anatomosis
The area to be resected and several centimeters of normal esophagus distal and proximal to it are mobilized. Umbilical tape or rubber drain tubing is placed around the esophagus and held in place with hemostatic forceps to occlude the lumen at a convenient distance from the area to be resected. A point is selected proximal/distal to the diseased segment, where the esophagus is sharply transected, leaving healthy tissue for closure. The mucosal-submucosal layer is apposed with 3-0 simple-interrupted monofilament sutures placed about 3 cm from the cut edge, 2 to 3 mm apart. The knots may be tied in the lumen. Tension on the sutures must be adequate to form a tight seal without interference of the blood supply.
The esophageal muscle is apposed with interrupted sutures of 2-0 suture material. The muscle layer has limited elasticity, and if necessary, a relief incision in the form of a circular myotomy 4 to 5 cm proximal or distal to the anastomosis can decrease tension on the repair
what instrument should not be used to manipulate esophagus during sx?
Crushing clamps of any type should not be used on the esophagus.
What distance are placed the mucosal-submucosal layer after removal of the diseased portion of esophagus?
The mucosal-submucosal layer is apposed with 3-0 simple-interrupted monofilament sutures placed about 3 cm from the cut edge, 2 to 3 mm apart
An extensive cervical esophageal stricture produced by annular stenosis of the entire wall may preclude successful repair by techniques described previously. how can you increase the diameteR?
The diameter of the equine esophageal lumen can be increased by using a patch graft of the sternocephalicus muscle or by esophagopexy to create a diverticulum
What muscles are used in a patch grafting?
the brachiocephalicus and sternocephalicus muscles serve as donors for the graft
Describe surgical approach of patch grafting
With the horse under general anesthesia, a ventral midline or lateral approach to the esophagus is made, and depending on location of the defect and the approach used, the brachiocephalicus and sternocephalicus muscles serve as donors for the graft. With a nasogastric tube passed to the level of the stenosis, a longitudinal incision is made through the muscularis from a point 3 cm distal to and extending 3 cm proximal to the stricture to the sternocephalicus muscle and periesophageal tissues to create a diverticulum has been described and decreases the chance of stricture formation. Type I stricture, suturing the incised esophageal musculature to the sternocephalicus muscle and periesophageal tissues to create a diverticulum has been described and decreases the chance of stricture formation. For Type II and III strictures, the mucosa and submucosa of the esophagus at the site of the stricture are sharply incised as the nasogastric tube is passed into the stomach. A caudal portion of the brachiocephalicus sternocephalicus muscle belly is mobilized by blunt separation of muscle fibers. This strip of muscle, the “graft,” should maintain its proximal and distal attachments and needs to be freely movable so as not to exert tension on the closure when the patient’s head and neck are moved. The graft should be wide enough to appreciably increase the lumen of the esophagus. The edges of the mucosa and submucosa are sutured to the muscle graft using 3-0 monofilament sutures in an interrupted through-and-through mattress pattern, and the edges of the muscularis are sutured to the graft with 3-0 simple interrupted sutures of monofilament suture material. Preplacement of mattress sutures and closure of both layers on one side of the esophageal defect at a time facilitates repair. The nasogastric tube should be removed before the second edge is closed. Suction drains are placed next to the esophagus, and the approach incision is closed.
For patch grafting describe the muscle sutured in Type I stricture
For a Type I stricture, suturing the incised esophageal musculature to the sternocephalicus muscle and periesophageal tissues to create a diverticulum has been described and decreases the chance of stricture formation
For patch grafting describe the muscle sutured in Type II and Type III strictures
For Type II and III strictures, the mucosa and submucosa of the esophagus at the site of the stricture are sharply incised as the nasogastric tube is passed into the stomach. A caudal portion of the brachiocephalicus sternocephalicus muscle belly is mobilized by blunt separation of muscle fibers. This strip of muscle, the “graft,” should maintain its proximal and distal attachments and needs to be freely movable so as not to exert tension on the closure when the patient’s head and neck are moved. The graft should be wide enough to appreciably increase the lumen of the esophagus.
How do you close the edges of mucosa and submucosa in patch grafting
The edges of the mucosa and submucosa are sutured to the muscle graft using 3-0 monofilament sutures in an interrupted through-and-through mattress pattern, and the edges of the muscularis are sutured to the graft with 3-0 simple interrupted sutures of monofilament suture material. Preplacement of mattress sutures and closure of both layers on one side of the esophageal defect at a time facilitates repair. The nasogastric tube should be removed before the second edge is closed. Suction drains are placed next to the esophagus, and the approach incision is closed.
Posoperatively you should give intravenous feeding or esophagostomy for how many days?
10 days
An indwelling tube in patch grafting stimulates salivation and consequently what?
fistula formation
What diagnostic challenge might small esophageal fistulas present?
Endoscopic findings and barium swallow esophagograms are often normal.
What symptoms should suggest an esophageal fistula?
Cervical swelling, fever, and dysphagia.
Figure 30-37. Positive-contrast esophagogram shows a large fistula remaining after removal of the esophagotomy tube. The cuff on the nasogastric tube prevents reflux of barium into the pharynx.
Figure 30-36. Endoscopic appearance of a large esophageal fistula. Smaller fistulas are often difficult to locate endoscopically.
Figure 30-36. Endoscopic appearance of a large esophageal fistula. Smaller fistulas are often difficult to locate endoscopically
Which diagnostic technique best demonstrates esophageal fistulas?
Contrast radiography using liquid barium under pressure.
How are large esophageal fistulas different from small ones?
Large fistulas can extrude copious amounts of masticated food and saliva.
What might be necessary if an esophageal fistula fails to heal spontaneously?
Resection of the sinus tract and closure of the esophageal stoma.
What surgical technique is used for closing esophageal fistulas?
The closure technique is similar to esophagotomy.
What is the difference between a traction diverticulum and a pulsion diverticulum?
Traction diverticulum involves outward traction of all esophageal layers, while pulsion involves protrusion of mucosa and submucosa through a muscular defect.
What are common causes of traction diverticulum?
Contraction of periesophageal scar tissue, post-traumatic wounds, or esophagostomy.
What can cause pulsion diverticulum in horses?
Fluctuations in intraluminal pressure or overstretch damage by impacted feedstuffs.
How do traction (true diverticulum) and pulsion diverticula appear on barium swallow esophagograms?
Traction diverticula are spherical with a wide neck, while pulsion diverticula are flask-like with a narrow neck.
When should a pulsion diverticulum be repaired surgically?
When it enlarges progressively, increasing the risk of obstruction and rupture.
What surgical options are available for repairing a pulsion diverticulum?
Diverticulectomy or mucosal-submucosal inversion with muscular reconstruction.
Which technique is preferred for repairing pulsion diverticula and why?
Mucosal inversion because it avoids entry into the esophageal lumen, reducing postoperative complications.
What is the most common type of esophageal cyst in horses?
Epithelial inclusion cyst lined with stratified squamous epithelium.
What symptoms may indicate the presence of an intramural esophageal cyst?
Dysphagia, regurgitation, palpable neck mass, and resistance to a nasogastric tube.
What imaging techniques confirm the presence of an intramural cyst?
Ultrasonography and contrast radiography.
How can an esophageal cyst be surgically removed?
Through enucleation, followed by inversion or resection of redundant mucosa. Longitudinal incision over the cyst and carfeful dissection separated from its position btw mucosa/submucosa and muscularis to remove intact close muscularis with simple int 3-0 absorb
What precaution is taken during cyst removal to avoid perforation of the esophageal mucosa?
Manipulating a nasogastric tube caudal to the cyst.
What is megaesophagus in horses?
Dilation and muscular hypertrophy of the esophagus oral to a constricted segment.
In which horse breed has megaesophagus been observed with higher prevalence?
Friesian horses.
What is achalasia, as seen in megaesophagus?
Failure of the distal esophagus to relax, leading to proximal dilation.
What was the suspected cause of megaesophagus in a foal as per one case report?
Vascular ring anomaly from a persistent right aortic arch.
What surgical procedure was attempted in a foal with megaesophagus but was unsuccessful?
A modified Heller myotomy.
What conservative treatment has been effective for congenital ectasia (dilation of unkown cause)?
Total confinement, avoidance of roughage, and intensive nursing care.
What is reduplication of the esophagus?
A condition where a dissecting tract develops parallel to or within the esophageal wall.
What is a clinical challenge in diagnosing esophageal reduplication?
It closely resembles other forms of esophageal obstruction.
What condition does esophageal reduplication resemble, complicating diagnosis?
It resembles tube feeding complications in Esophagostomy making diagnosis difficult
What is the most common neoplasm causing esophageal obstruction in horses?
Squamous cell carcinoma.
Where was squamous cell carcinoma located in reported cases?
In the tracheal bifurcation and the distal cervical esophagus.
How can an early diagnosis of esophageal neoplasms be made?
Through biopsy and cytology of brush samples obtained via endoscopy.
What diagnostic tool can detect advanced esophageal neoplasms?
Radiography.
Why might surgical resection of esophageal neoplasms be of limited value?
Due to questionable outcomes and the risk of recurrence.
What condition may be confused with an intramural esophageal cyst on examination?
An abscess.
What is the primary symptom of idiopathic muscular hypertrophy in horses?
It is often asymptomatic.
What tissue changes were observed in megaesophagus cases involving Friesian horses?
Disorganized collagen deposition and decreased neural elements.
What is the surgical risk when a pulsion diverticulum is very narrow?
Postoperative leakage and stenosis.
What is the preferred method of closing a cyst-induced sac in the esophagus?
By inversion (avoid enter esophageal lumen), to avoid complications like infection and fistula formation.
What type of esophagoscopy finding might suggest the presence of an esophageal diverticulum?
Size and configuration of the opening into the diverticulum.
What differentiates traction and pulsion diverticula based on clinical signs?
Traction diverticula produce few symptoms, while pulsion diverticula can cause obstruction.
What complication can arise from second-intention healing of an esophagostomy?
Formation of a traction diverticulum.
Figure 30-43. (A) A pulsion diverticulum repaired by inversion of the mucosal/submucosal sac with reconstruction of the muscular layer. (B) The edge of the muscular defect should be débrided back to healthy tissue. (C) The sac is inverted, and the edges of the muscularis are apposed with simple-interrupted sutures of 3-0 polypropylene in a manner that avoids undue tension on the closure and prevents stenosis of the esophageal diameter.
Figure 30-44. (A) Double-contrast study of pulsion diverticulum. (B) Exposure of muscular defect at surgery
Describe the surgical procedure of pulsion diverticulum inversion
Esophagus exposed and and defect on muscularis ID. The edges of the muscular defect can be débrided back to healthy-appearing tissue. The sac is inverted, and the edges of the muscularis are apposed with simple-interrupted sutures of 3-0 polypropylene in a manner to avoid undue tension on the closure and prevent stenosis of the esophageal diameter (Figures 30-44, A–C). Postoperatively, feeding should consist of soft foods for 4 to 6 weeks.
Figure 30-46. Barium esophagogram shows the classic appearance of an intramural lesion of the esophagus—in this case, an epithelial inclusion cyst. The esophageal lumen is narrowed caudad and is dilated but not filled with barium craniad because the mural mass produces a filling defect.
What should you do if the intramural cyst and muscoa is inadvertently entered?
You should marsupialize by suturing the capsule of the cyst
What should be done if extreme amounts of saliva leak through the esophageal incision?
The incision should be completely opened and lavaged daily.
What are potential complications if saliva is not removed from the periesophageal tissues?
Mediastinitis or pleuritis can occur.
What is a major risk of placing a dislodged feeding tube into a dissection plane or the thorax?
It can lead to a dissecting infection with an unfavorable outcome.
How can the patient’s nutritional needs be met in cases of esophageal dehiscence?
By oral feeding, placement of a feeding tube, or parenteral nutrition.
Why is parenteral nutrition less commonly used in cases of esophageal dehiscence?
It is expensive and requires strict monitoring.
What is the most common complication after treatment of an annular esophageal lesion?
Stricture formation.
What is one option for managing an esophagostomy to prevent stricture formation?
Allowing it to heal as a traction diverticulum.
What electrolyte imbalances result from large daily losses of saliva?
Hyponatremia, hypochloremia, and transient metabolic acidosis.
What type of metabolic disturbance follows transient metabolic acidosis due to salivary loss?
Progressive metabolic alkalosis.
How is the electrolyte imbalance corrected in patients with large salivary losses?
By daily oral administration of sodium chloride.
How is metabolic alkalosis corrected in cases of electrolyte imbalance from salivary loss?
Through renal compensation mechanisms.
What can chronic feeding tubes placed in the distal third of the cervical esophagus cause?
Jugular vein or carotid artery ulceration.
What should episodes of bleeding in a patient with a feeding tube in the cervical esophagus indicate?
The need for exploratory surgery and vessel ligation to prevent exsanguination.
What is the main surgical risk when treating esophageal dehiscence?
Breakdown of the sutured incision and potential for infection.
What is one method of preventing pleuritis or mediastinitis following esophageal dehiscence?
Draining dissection planes ventrally along the trachea to the outside.
