moyaser g. thanoon,

Digestive system | Surgery of the digestive system | Dr. Moyaser G. Thanoon Page | 1

Moyaser G. Thanoon, BVMS, MSc, PhD

Assistant professor, Department of Surgery and Theriogenology

College of Veterinary Medicine, University of Mosul, Mosul, Iraq

https://orcid.org/0000-0002-5272-4882

https://www.researchgate.net/profile/Moyaser_Thanoon

Digestive system | Part I | 5th

year 2019

Surgery of the digestive system

Surgical Affections of the lips

1- Trauma

Occurs due to car accidents, protruding objects or attacks by dogs, because of the excellent blood

supply the healing is usually rapid.

In severe laceration or loss of tissue plastic surgery is needed to preserve the normal function of lips

and checks.

2- Harelip (cleft lip)

This is a cleft in the upper lip which often runs into the nostrils.

It may be unilateral or bilateral and is often associated with cleft palate and split jaw.

It is most common in calves and occurs due to genetic origin.

Treatment

Under G.A. the edges of the cleft are excised so that the mucous membrane and the skin are

separated. Then the M.M. edges are sutured together, using silk or nylon, while the skin edges then

united by simple interrupted sutures using the same suture material.

Tooth Surgery

Tooth Anatomy:

The basic anatomy of a tooth it’s have a crown above the gingiva (gum line) and a base below the gum

line. If the teeth are in a socket, the base is called the root.

The tooth is formed from:

Enamel: which forms the surface of the crown and which is the hardest substance.

Dentine: bonelike material, but harder than bone.

Pulp cavity: which is a space in the center of the tooth filled with pulp (a mucous connective tissue

that supports blood vessels and nerves).

Root canal: which is an extension of the pulp cavity into the root (the root canal terminates at the

apical foramen.

Cementum: which is a bone-like structure that attaches the tooth to the socket with the aid of the

periodontal membrane or ligament.


Teeth Affections

Classified into: Congenital; Acquired

Congenital: -

1. Persistent deciduous teeth:

One or more smaller, white deciduous tooth often remains next to or in place of a permanent one.

They are off symmetrically arranged, such as both canine in the maxilla of dog.

Causes:

The deciduous tooth is persistent when its root is not resorbed under the pressure of the erupting

permanent tooth, and the deciduous tooth is not pushed out of its alveolus.

Treatment:

Extraction of the persistent deciduous tooth

2. Oligodontia

Several deciduous or permanent teeth are not present.

Causes:

Hereditary missing of tooth germs. But, not every kind of oligodontia is hereditary, because tooth

germs may be destroyed by traumatic or infectious influences.

3. Polydontia, Supernumerary, Hyperdontia

It's an increasing in a number of equal teeth, which caused by persistent deciduous teeth.

Clinically

The differentiation between a persistent deciduous tooth and a permanent tooth is facilitated by X-ray,

to shows the length and size of the root.

The supernumerary teeth stand next to or in the molar region and may have no counterparts on

opposing side.

Food may become impacted between the supernumerary tooth next to the molar region and the regular

tooth, and putrefaction and gingivitis may results.

Even the movement of the tongue may be hindered and painful erosion in the buccal mucosa may

develop.

Causes:

Division or double disposition of one or several tooth germ is the source of extra teeth.

Treatment:

Extraction of the troubled extra tooth.

4. Abnormalities in the position and direction of the teeth

The incisors teeth may be found overlapping or taking a transverse or oblique direction, or rotated

on their long axis.


Unequal length of the upper and lower jaws prevents their incisors coming into contact with the result

that they become excessively long from want of wear and that those of the shorter jaw may penetrate

the soft tissues opposite.

Parrot mouth:

When the upper incisors overhang the lower.

Pig or Sow mouth:

When the lower incisor protrude beyond the upper.

Some time the teeth are not close together, but have space between them in which food material

lodged, irritating the gum and perhaps leading to its separation from the teeth, and opening the way for

infection into the alveolus to cause alveolar periostitis.

Treatment:

Shortening or extraction offending tooth.

5. Hypoplasia and Discoloration of teeth

Hypoplasia of Enamel:

Occur during the development of the permanent teeth, causing smooth mineralization of the teeth.

It is hereditary and also occurs due to intense infestation with worms, pneumonia, gastroenteritis,

osteodystrophy and traumatic lesions.

Hypoplasia of Cement:

For unknown reasons, possibly including systemic disease during dentition or a hereditary defect, the

enamel invaginations on one or several posterior teeth may not be filled with cementum, but the tooth

or teeth are not carious.

Discoloration of teeth:

A yellow discolouring indicates a deposition of tetracycline during dentition.

The stain deposit in the bone and hard tooth substances during mineralization.

So that, Tetracycline should not administered during the 1st month of life.

Also the yellow discoloring of teeth result when animals are intensively fed on carrots, apples and

pears.

Acquired:

1. Dental Caries:

Caries is destruction or decay of the cement, dentine and enamel of the teeth, caused by

carbohydrate-fermenting bacteria. The bacteria produce acid that attack the surface of the tooth

Treatment:

Extracting the diseased tooth or teeth.

2. Dental Calculus or Dental Tarter:

It's commonly seen in the premolars, as a hard deposit of calcium salts and organic materials.

The tarter is brown to black or greyish-brown in colour formed from the fluid of the mouth.

Tarter does not cause any clinical signs, unless it involves the gingival border in which case, primary,

marginal gingivitis may cause separation between gum and tooth, and this lead to periodontal disease,

as a result of bacterial infection.

Treatment:

Crack off the deposit with incisor forceps

Scale the teeth with tooth scaler.


3. Fracture of teeth:

It's common in dogs and cats. Rarely cause clinical signs.

Etiology:

External trauma (car accident); Biting on hard objects (stones or sticks).

The fracture may extend into the pulp cavity.

Fractures that extend into the dentine, but not into the pulp, are partially repaired by the laying down

of reparative dentine by odontoblasts on the inner surface of the dentine.

4. Odontoma:

Tumor of teeth, arise from any or combination of various mesodermal elements making up the angle

of the tooth.

The tumor may be any where within the former and then often in the body of the jaw.

Treatment:

Consist of cutting out the Odontoma under general anesthesia and closing up the cavity as well as

possible, suturing the surrounding tissues over it.

5. Epulis:

Neoplasm involves the gingival, often at the dental border or interdentally. It is usually a fibroma.

Treatment:

Removed by thorough dissection under general anesthesia.

Affections of the Tongue

1. Trauma:-

Trauma of the tongue occurs in all species of animals, and all the affected animals will show the

following sings.

Inability to protrude the tongue for feeding; Salivation; Halitosis.

Treatment

Cleaning of the area after insertion of mouth gag and application of local antiseptics and antibiotics.

2. Lacerations:-

Can occur after street accident or by sharp tooth fragment, if laceration are deep, suture under G.A.

and a tension suture (vertical mattress) and non absorbable suture material are used.

In case of severe laceration partial glossectomy was done.

Amputation in cattle must be avoided because of the loss of prehensile function of the tongue.

Surgical procedure of partial glossectomy

1- The animal is anesthetized and placed in lateral recumbency.

2- A tourniquet (rolled gauze) is applied proximal to the intended transaction site.

3- The tongue is transected dorsal and ventral to the lacerated site (the incision will take V shape).

4- The dorsal and ventral aspects are sutured together with an interrupted horizontal mattress pattern

with no. 1 or 2 non-absorbable sutures.


3. Snake bite:-

The tongue can be bitten by a snake as it protruded to bring grass or hay into the mouth.

Clinical sings

Gangrene and septicemia.

Swelling of the intermandibular region.

Swelling of the tongue and discolored and protruded stiffly from the mouth.

Treatment

Immediate local and I.M. injection of antivenom and antibiotics (penicillin and streptomycin)

is essential.

Giving water and feed.

Incise the tongue to drain away exudates.

4. Paralysis of the tongue (glossoplegia):

Paralysis of the hypoglossal nerve and the tongue showed one side of the mouth. In bilateral

paralysis the whole tongue is flaccid and hangs out of the mouth.

Causes

Infection or neoplasm along the course of the nerve.

Lead poisoning and botulism.

Treatment

Tonics.

Water and nutrients must be administered by stomach tube.

5. Neoplasia:-

Tumor of the tongue are very uncommon, but the one usually seen is the squamous cell carcinoma.

The treatment is excision of the tumor or amputation if it is possible.

6. Self suckling

If nose ring with burr is not successful for preventing self suckling a partial glossectomy is used.

The technique alters the tongue contour to prevent from forming a U shaped tongue for suckling.

(Alter from concave to convex shape)

Surgical procedure:

The operation is performed by sedation with local infiltration of lidocaine or under general

anesthesia.

Two techniques could be performed:

A. Ventral partial glossectomy:

A two elliptical incision is made at the ventral mucosa that is approximately 5cm at its widest part and

start rostral to the frenulum attachment on the tongue and extends rostrally 2.5cm caudal to the tip of

the tongue.

The edges closed with horizontal mattress suture pattern.

B. Lateral partial glossectomy:

Removes half of the tip extends 5cm of the tongue removed.


Salivary Glands (S.G.)

The major salivary glands are located some distance from the oral cavity and empty their secretions

via long ducts.

They include:

1- Parotid S.G.

2- Mandibular S.G.

3- Sublingual S.G.

- Zygomatic S.G. or Buccal S.G.

- Smaller ones present at soft plate, lips, tongue

In dogs there are 4 main pairs of salivary glands:

Parotid, mandibular, sublingual, and the zygomatic glands, which are the dorsal buccal glands in other

animals.

In horses and ruminants there are 3 main pairs of salivary glands:

Parotid, mandibular, and sublingual glands.

The parotid gland is the largest of these glands and occupies the space between the vertical ramus of

the mandible and the wing of the atlas.

The parotid duct (Stenson's duct) is formed by three or four radicles and leaves the gland ventrally

about 2.5cm above the external maxillary vein.

Affections of the salivary glands

Salivary glands affection divided into 2 types:

1- Congenital

2- Acquired.

Congenital abnormalities of the salivary glands are associated with agenesis or atresia of the parotid

ducts, resulting in a fluid-filled swelling proximal to the obstruction site.

Acquired diseases:

Usually secondary to lacerations or other trauma that ruptures the salivary glands or ducts.

1. Trauma:-

Fresh wound of the gland must be sutured after thorough cleaning and debridement, the leaking wound

has a great tendency toward spontaneous closure.

Close the wound where the fistula has been excised in several layer with cat gut, the skin wound is

closed with interrupted silk suture. The tube facilitates normal drainage of saliva.

2. Salivary Mucocele

A salivary mucocele (or sialocele) is an accumulation of saliva in the submucosal or

subcutaneous tissues after damage to the salivary duct or gland capsule.

This is the most common salivary gland disorder of dogs.


Although any of the salivary glands may be affected, the ducts of the sublingual and

mandibular glands are involved most commonly.

Parotid salivary duct obstruction occurs when the saliva can’t flow normally from parotid

gland into mouth.

Saliva often collects in the intermandibular or cranial cervical area (cervical mucocele).

It can also collect in the sublingual tissues on the floor of the mouth (sublingual mucocele or

ranula).

A less common site is in the pharyngeal wall (pharyngeal mucocele) or lower eyelid

(zygomatic mucocele).

Causes of Salivary Mucocele and duct obstruction:

The cause may be traumatic or inflammatory blockage or rupture of the duct or capsule (with

damage of parenchyma) of the sublingual, mandibular, parotid, or zygomatic salivary gland.

Salivary gland stones made of calcium and other minerals (most common)

Scar tissue

Mucous plugs

Foreign bodies

Abnormal growth of cells

Usually, the exact cause is not determined, but a developmental predisposition in dogs has

been suggested.

Symptoms of Salivary Mucocele

Signs depend on the site of saliva accumulation.

In the acute phase of saliva accumulation, the inflammatory response results in the area being

swollen and painful.

The first noticed sign may be a nonpainful, slowly enlarging, fluctuant mass, frequently in the

cervical region.

A pharyngeal mucocele can obstruct the airways and result in moderate to severe respiratory

distress.

A zygomatic mucocele may result in exophthalmos or enophthalmos, depending on its size and

location.

A mucocele is detectable as a soft, fluctuant, painless mass that must be differentiated from

abscesses, tumors, and other retention cysts of the neck.

Diagnosis of salivary mucocele and duct obstruction

Salivary mucocele usually can be diagnosed by palpation and aspiration of light brown or

blood-tinged, viscous saliva.

Careful palpation with the animal in dorsal recumbency can determine the affected side

Imaging tests for diagnosis:

o Sialography X-rays and computer technology create cross-sectional images.

o CT. scan this is currently the test of choice.

o Ultrasound. High-frequency sound waves are used to see tissue and organs inside the

body.


Treatment of salivary mucocele and duct obstruction

Surgery is recommended to remove the damaged salivary gland and duct.

Periodic drainage if surgery is not an option is usually only a temporary measure and has the

potential for iatrogenic infection.

Gland-duct removal has been recommended for curative treatment of salivary mucoceles.

Marsupialization

Marsupialization:

The duct proximal to the obstruction can be marsupialized to the oral cavity by the following surgical

technique:

A longitudinal incision is made in the oral cavity at the level of the distended duct.

Saliva will leak out into the incision.

The incision is enlarged so the stoma created is 1-1.5cm.

The oral mucosa is sutured to the duct mucosa with a simple interrupted pattern of absorbable

suture of 2/0 or 3/0 size.

A size 5 to size 8 French polyethylene catheters should be passed through the newly formed

stoma and sutured to the buccal mucosa to prevent unwanted closure.

Ranula in Dogs:-

This is a large, transparent, circumscribed, well-defined salivary cyst that forms in the mouth on either

side of the tongue.

The cause has been related to lesions of the mandibular and sublingual ducts.

Treatment of ranula presents problems because if they are incised they tend to recur.

The cyst has a thin, fragile wall, and usually is located at a relatively inaccessible site on the floor of

the mouth.

Though I.M. injection of corticosteroids has been reported to cause regression of the lesion, this result

is not consistent.

Surgical drainage of ranula by excising an elliptical, full-thickness section of the mucocele wall, suture

the lining wall of the mucocele with the sublingual mucosa to provide drainage for several days.

3. Salivary Fistula

Salivary fistula is an uncommon problem that can result from trauma to the mandibular,

zygomatic, or sublingual salivary glands.

Wounds of the parotid gland are most likely to develop a fistula.

Parotid duct injury may be the result of a traumatic wound (eg, bite wound), abscess drainage,

or prior surgery in the area with iatrogenic rupture.

The constant flow of saliva prevents healing, and a fistula develops.

A salivary fistula must be differentiated from a draining sinus (due to a penetrating foreign

body or endodontic disease of a mandibular tooth) in the neck or from sinuses arising from

congenital defects.


Treatment of Salivary Fistula

Surgical ligation of the salivary duct.

Excision of the associated gland may also be necessary.

Destruction of salivary gland.

Destruction of salivary gland

The salivary gland may be injected with a caustic agent to destroy the secreting cells until the fistula

resolves and heals.

Use of 10 to15 ml of Lugol's iodine or up to 35 ml of 10% buffered formalin injected through a

catheter placed into the duct, the duct must be held closed for a few minutes to achieve the diffusion of

the caustic agent throughout the gland.

Post treatment glandular and peri-glandular swelling may require an anti-inflammatory agent such as

acetylsalicylic acid or Flunixin meglumine.

4. Salivary Gland Tumors

Salivary gland tumors are rare in dogs and cats, although cats are affected twice as frequently

as dogs.

Most are seen in dogs and cats >10 years old.

Most salivary gland tumors are malignant, with carcinomas and adenocarcinomas.

Local infiltration and metastasis to regional lymph nodes and lungs are common, as is local

recurrence after surgical excision.

Radiotherapy, with or without surgery, offers the best prognosis.

5. Sialoliths (Salivary Calculi)

Sialoliths are seen more often in horses than in the other species, Stenson's duct is the usual site.

The stones have different size, some with a diameter of several inches have been reported.

These calculi consist mainly of calcium carbonate and generally requiring a nucleus for the deposition

of calcium salts. This nucleus can be provided by a small foreign body entering the ostium of the duct

or by cellular debris.

Diagnosis is by the swelling of the duct and regional gland, and by palpation of the stone in the duct.

Surgical treatment

The operation can be done under local analgesia and tranquilizer, but a general anesthetic is

usually preferable.

Make an incision over the swelling along the course of the duct, taking care to avoid

accompanying veins and arteries.

Expose the calculus and remove it.

Suture the duct with catgut using continuous pattern.

Close the skin with interrupted silk stitches.

Cleft Palate (palatoschisis)

Cleft palate is a congenital defect.

An interruption may occur in the process of normal fusion at any stage so that it is possible to have

any degree of cleft, from a complete cleft of both hard and soft palates to a small cleft in the caudal

part of the soft palate only.

In man the congenital factors include, gene mutations, chromosomal aberrations, and environmental

teratogens.


Clinical signs:

Dysphagia with reflux of milk or food material through the nostrils.

The presence of a cleft is confirmed by direct visual or endoscopic examination or both.

Aspiration pneumonia is also commonly present due to inhalation of milk that has passed from

the oral cavity to the nasal cavity.

Epiglottic entrapment may accompany the condition.

Diagnosis:

Clinical sings.

Oral or endoscopic examination.

Treatment:

Surgical correction of the palate (Palatoplasty).

In the horse 3 approaches have been described to repair cleft palate:

A) Oral approach, may be used for foals less than 30 days old. The oropharynx is more accessible at

this age, in contrast to older patients, as subsequent growth of the head makes it relatively narrower.

B) Pharyngostomy approach, may be effective in repairing limited defects in the caudal soft palate,

although surgical exposure is limited.

C) Mandibular symphysiotomy, although this is a rather extensive, and invasive approach, it allows

full visualization procedure of the hard and soft palates, and is suggested as the procedure of choice.

Principles should be aimed to close the cleft palate:

1- Adequate mobilization of the tissues to be sutured.

2- Apposition of fresh wound edges.

3- Anatomical closure of the defect without excessive tension.

Palatoplasty is performed with the animal under general anesthesia in dorsal recumbency.

The animal is intubated through a tracheotomy.

Hard palate cleft repair:

Small defects of the hard palate can be repaired using:

Mucoperiosteal sliding flap technique.

Large defect of the hard palate may be best repaired by the:

Mucoperiosteal reflected- flap technique.


Soft cleft palate repair:

Excision of the mucosal edges surrounding the cleft.

Suture the nasal mucosa and the muscular layer with a simple interrupted pattern using

absorbable suture material.

The oral mucosa sutured with a horizontal mattress pattern using monofilament non

absorbable suture material.

The major complication of this operation is the dehiscence of the cleft soft palate repair.

Pharynx

The pharynx consists of three (3) parts:

Nasopharynx

Oropharynx

Laryngopharynx

Surgical affection of the pharynx

1. Trauma

The most pharyngeal injuries occurs by sharp objects that are taken by the mouth can damage the

pharynx.

Clinical sings

Blood tinged saliva.

Dysphagia.

Coughing.

Dyspnea.

Swelling of the cranial part of the neck.

Diagnosis

Clinical sings.

Radiography.

Pharyngeoscope.


Treatment:-

Removal of the foreign body.

In dogs general anesthesia may needed for removal of the foreign body.

Most laceration in the pharynx heals quickly without being sutured.

2- Retropharyngeal abscess in dogs

Abscess formation in the dorsocaudal wall of the pharynx usually is the result of a foreign body's

penetration.

Clinical sings

The neck is held stiffly.

Local pain and swelling with dysphagia.

High temperature is present.

Diagnosis

Confirmed by withdrawing exudates from the swollen area and by radiographic examination.

Treatment

General anesthesia with intubation of the dog.

The head is positioned lower than the rest of the body so that the contents of the abscess will

drain cranially.

Antibacterial sensitivity test should be conducted to guide the subsequent therapy.

3- Pharyngeal cyst

It is a space occupying lesion of the pharynx that are capable of causing clinical sings related to air

way obstruction or dysphagia.

The most frequent location of this obstruction is beneath the epiglottis.

Etiology

Developmental or acquired, it have been suggested that the sub epiglottic cyst may be a remnant of the

embryonic thyroglossal duct or post traumatic inflammatory lesion.

Clinical sings

Respiratory noise during exercise.

Coughing, nasal discharge, dysphagia and dyspnea at rest.

Diagnosis

1- Clinical sings.

2- Endoscopic examination.

Treatment

Resection of pharyngeal cyst is accomplished through ventral laryngotomy approach with the patient

in dorsal recumbency.

Cyst structure located in sub epiglottic area is grasped with pair of forceps, the cyst should be elevated

and dissected from the mucosa.

4- Foreign bodies

Though foreign objects are rarely found in the pharynx, they often lodge in the peripharyngeal area.

Sticks, bones, needles and other sharp objects may penetrate the wall of the pharynx.

Clinical signs

Sudden development of dysphagia.

Pain.

Restlessness.

Salivation sometimes tinged with blood.

Coughing and vomiting.


Diagnosis

1- Examination is done after general anesthesia.

2- Large objects may be palpated or seen directly.

3- Other foreign bodies may found only by radiograph.

4- Abscess in the inter-mandibular space may result from penetrating foreign object such as needle.

5- Foreign objects tend to migrate because of the motion during mastication and swallowing.

Treatment

1. Large object are readily identified and removed.

2. Small object require a longer search and several lateral and dorsoventral radiographs may be

required.

3. The area should be bluntly dissected with care because of the large numbers of blood vessels

and nerves.

4. Some objects may penetrate so far that they are need an incision through the ventral cervical

region.

5. Excessive damage by prolonging the search for a foreign body should be avoided.

6. Healing after removing the objects usually is uncomplicated.

5-Tumor

Primary tumors of the soft palate and pharynx are rare, but are readily recognized on physical

examination in dogs.

Invasive malignant tumors such as fibrosarcoma, Myxosarcoma and melanoma, are not

uncommon.

Neoplasms of the soft palate may extend into the pharynx to obstruct breathing and

swallowing.

The resultant sings include, dysphagia, coughing, and emaciation due to inability to swallow.

As tumors affecting the pharynx usually are malignant and often metastatic, the prognosis is

poor.

Surgical removal of the neoplasm may be attempted to identify the type or relieve the dyspnea

and dysphagia with scissors or with electro scalpel.

Pharyngostomy

The operation is designed to by-pass the oral and pharyngeal cavities by creating a pharyngeal fistula.

A flexible tube may then be passed through the fistula from the lateral surface of the neck, down to the

esophagus and into the stomach.

This method used to feed animals that are unable to ingest food orally because of cleft palate,

mandibular or maxillary fracture, or esophageal diseases.

Surgical technique

1. Under general anesthesia the animal kept in lateral recumbency, and an area at the neck prepared for

aseptic surgery.

2. An index finger is inserted through the mouth into the pharynx near the base of the tongue and

pushed laterally. This will cause a bulging at the exterior surface of the neck just caudal to the

stylohyoid muscle in the retromandibular space.

3. A large curved forceps is used to replace the finger, a small skin incision made over the bulging,

and the forceps pushed through the mucosa and skin incision to the surface.

4. A flexible plastic tube of suitable diameter and length is then grasped by the forceps and drawn into

the pharynx.


5. Then the tube is passed down the esophagus and into the stomach.

6. The tube is secured to the skin with a purse-string suture and capped.

7. Following removal of the tube, the wound will heal quickly with minimal scaring.

Esophagus

It is a musculo-membranous tube serves to carry food, water and saliva from the pharynx to the

stomach. It is divided into cervical, thoracic and short abdominal part.

Structure of esophagus:

The esophageal wall consists of 4 layers:

1. Tunica adventitia:-

Loosely connects the esophagus to neighboring structures and allows freedom to move during

swallowing and when the animal bends its neck.

2. Tunica muscularis (muscular coat):-

By a wave like contraction moves the bolus toward the stomach or during regurgitation in ruminants

toward the mouth.

3. Tunica submucosa: -

Loose connective tissue

4. Tunica mucosa (mucous membrane):-

Covered with stratified squamous epithelium, which is cornified particularly in herbivores.

Nerve and blood supply of esophagus:-

Innervations derived from the vagus and sympathetic trunk.

Blood supply of cervical part: Supplied by branches of the right and left common carotid arteries.

Blood supply of Thoracic part: by the bronchoesophageal artery.

The most important relations of the cervical part:-

Common carotid artery.

Jugular vein.

Trachea.

Cervical lymph nodes.

Vagosympathatic trunk.

Caudal (recurrent) laryngeal nerve.

Thymus in young animals.

Course of esophagus:

The esophagus begins at the level of the first cervical vertebra (C1) where lies dorsal to the trachea.

Then esophagus becomes left to the trachea until the thoracic inlet is reached.

In the thorax the esophagus continues dorsally and to the left of the trachea and to the right of the


aortic arch. From tracheal bifurcation to its termination at the stomach, the esophagus lies slightly to

the right of midline.

Surgical affections of the esophagus

1. Dilation of the esophagus (Mega-esophagus):

This can involve large segments or the whole of the esophagus which is then flaccid and

aperistaltic.

This is a congenital defect and seen most often in foals and it is a lethal abnormality.

It is manifested by milk or ingesta reflux from the nostrils and after ingestion of solid feed a

doughy enlargement of the esophagus extending from the area of the larynx to the thoracic

inlet.

Passing a stomach tube is difficult.

Death occurs as a result of inhalation pneumonia or asphyxia.

Other causes of esophageal paralysis may be caused by intoxication and intracerebral infection.

2. Fusiform or cylindrical dilation:

It occurs following obstruction, this dilation extends from distal point of obstruction for a variable

distance. This continues until the normal diameter has been regained.

3. Pulsion diverticulum:

It occurs at the site of a gross localized distention caused by rounded body lodged inside the

esophagus like a turnip. This tend to recover spontaneously unless the distention propagated,

repeated accumulation of ingesta or unless there is rupture of muscle fibers in which case the

diverticulum must repaired surgically.

4. Traction diverticulum:

It is not caused by lodged foreign body inside the esophagus but results from paraesophageal

inflammation leading to a fibrous tissue formation, contraction, and drawing out of a section of the

esophageal wall.

5. Narrowing of the esophagus:

The causes of esophageal narrowing are:-

1. There is a stricture from formation of scar tissue as a result to a wound caused by sharp objects

after local pressure, necrosis or after esophagotomy. It can also occur after severe esophagitis

particularly from caustics.

2. Neoplasia of the esophagus particularly squamous cell carcinoma and papilloma decreases the

diameter of the lumen.

3. Abscess of the esophageal wall.

4. Pressure from outside the esophagus causes obstruction to the passage of feed, and in

ruminants may cause chronic bloat e.g. enlargement of the mediastina lymph nodes in cattle

(often tuberculosis).

5. Goiter if large causes pressure on the esophagus.

6. In dogs narrowing due to injury following general anesthesia caused by reflux of acidic gastric

contents.

7. In dogs also infestation of Spirocerca lupi causing granulomatus growth in the esophagus and

narrowing.


Common esophageal problems in cattle

The most important surgical problem involving the esophagus is choke or obstruction caused

by foreign objects.

In adult ruminant this problem may require immediate attention, as blockage of the esophagus

will limit or prevent the eructation of gases produced by fermentation in the rumen.

Delay treatment may lead to death from the respiratory disturbance due to tympany.

Common objects cause choke in cattle:

1. Potatoes, fruits and other vegetable roots.

2. Compression the lumen of the esophagus by space occupying lesions, as lymphosarcoma of

thymus, or mediastina lymphadenopathy.

3. Trauma may be caused by stomach tube passage, chemical irritation from medicated boluses

in the esophagus.

4. Damage caused by the lesions of migrating Hypoderma larvae.

Note: All cattle exhibiting sings or symptoms of choke must be classified as having rabies until choke

is proved.

Clinical sings:

History of eating particular food stuff.

Bloat.

Tenesmus.

Urine dibbling.

Retching and salivation.

Treatment:

1. If the object can be palpated in the cervical area it may be possible to restrain the animal and

retrieve the object manually from the esophagus.

2. If it cannot be reached, one may pass stomach tube and try to push the object into the rumen.

3. If the object lodges at the cardiac area, a rumenotomy may have to be performed to allow the

surgeon to reach through the cardia and retrieve the obstructing object.

Common esophageal problems in horses

Obstruction of esophagus caused by:

Foreign bodies

wounds

Stricture or narrowing

Diverticulum

Dilation

Esophageal spasm.

Clinical signs:

Ptyalism.

Dysphagia.

Regurgitation of food, water and saliva from the mouth and nostrils.

Coughing.

Some horses will show distress and sweating.

Extension of head and neck.

Diagnosis:

1. Clinical examination. 2. Radiology. 3. Endoscopy


Esophageal fistula

Its mean presence of fistulous tract connecting the lumen of the esophagus with the skin at the left of

the neck

Causes:

1. Penetration with FB

2. Trauma

3. Bite wound

4. Suture dehiscence

Signs: presence of an opening discharging food

Diagnosis

- Contrast radiograph

- Passing probe through opening

Treatment:

Surgical excised of fistulous tract

Debridement

Suturing wound edge

Esophagotomy

Surgical consideration

1. Esophagus not covered with serosa like other GIT organs which promotes a rapid seal due to

exudation of fibrin.

2. The musculature of the esophagus is weak and holds structure poorly.

3. The mucosa is relatively strong and holds tension.

4. Non absorbable suture material is used to close the mucosa rather than catgut which absorbed

quickly.

5. Short blood vessels require care and limitations in mobilizing the esophagus.

Surgical procedure

1. A 6-8 cm incision is made on the ventral midline of the neck at the junction of the middle and

lower third.

2. The incision is continued between the paired sternothyroideus and sternohyoideus muscles.

3. The trachea is identified and retracted to the right to expose the esophagus (stomach tube can

be introduced as a guide for identification of esophagus) and gently the esophagus is drawn a

way from the carotid sheath.

4. 1-2 cm incision is made in the muscular layer of the esophagus, and then the incision is made

in the mucosa.

5. The mucosa is closed with 2/0 or 3/0 polypropylene in a simple or continuous pattern, and the

knot tied within the lumen.

6. The muscle layer is closed with 2/0 polypropylene or polygalactin 910 (vicryl).

7. Fenestrated suction drain is placed beside the esophagus and exits the skin caudal to the skin

incision and maintained 24 hours to remove serum and blood from the surgery site.

Supportive medical treatment of esophageal obstruction:

Fluid loss due to esophageal obstruction particularly through saliva is present especially in

cattle, so there is considerable loss of bicarbonate and other electrolytes.

Any signs of acidosis must be treated by adding sodium bicarbonate to the infusion fluid which

is normal saline and 5% dextrose.

In horse and cow it is usually necessary to infuse at least 5 lit. i/v twice daily.


Esophageal Anastomosis

Necrotic tissue or extensive perforations with necrosis are indications for esophageal resection and

Anastomosis.

Surgical procedure:

1. After exposure of the esophagus, the operative field should be packed off with moistened pads

to prevent contamination with esophageal contents.

2. The esophagus stabilized by an assistant with the index and thumb fingers of each hand

(clamp) to minimize contamination.

3. The diseased portion of the esophagus is resected.

4. All necrotic tissue should be excised, and shreds of tissue and muscle should be carefully

debrided to expose healthy tissue.

5. Three stay sutures are placed at equal distances around the esophagus in healthy tissue. These

sutures facilitate gentle handling of the esophagus and help to maintain apposition of the cut

ends.

6. The mucosa is now closed with simple interrupted sutures of 2/0 polypropylene. The sutures

should be about 2mm apart and include a 2mm bite of mucosa. All knots of the mucosal

sutures should be lying in the lumen.

7. The muscular layer closed with interrupted horizontal mattress sutures of 3/0 polygalactin.

Postoperative Care and Assessment:

Oral intake should be withheld for 24-48 hrs.

Intravenous fluids should be continued until oral intake resumes.

Gruel food offered during the next 5-7 days.

If oral intake is not anticipated or possible within 48-72 hrs after surgery, feeding should be

performed via a stomach tube.

moyaser g. thanoon,

Documents