Difference between revisions of "Hiatal Hernia"

Revision as of 17:07, 7 August 2009

Typical Signalment

Sharpei dogs are predisposed to this disorder.

Description

A hiatal hernia is a diaphragmatic abnormality that allows part of the stomach and the abdominal oesophagus to prolapse into the thoracic cavity. Two types of hiatal hernia have been recognized in the dog and cat:

Sliding hiatal hernia - Cranial displacement of the distal oesophagus and stomach into mediastinum through the oesophageal hiatus.

Para-oesophageal hiatal hernia - Cranial displacement of part of the stomach into mediastinum through a defect adjacent to the oesophageal hiatus

An oesophageal stricture is an abnormal circumferential narrowing of the lumen secondary to severe oesophagitis. A deep wall injury results followed by healing by fibrosis. The most important causes are:

Chemical injury from swallowed substances
Gastro-oesophageal reflux
Foreign bodies
Oesophageal surgery
Neoplasia
Oesophageal abscesses

Diagnosis

Clinical Signs

Depend on the severity and extent of the stricture but include:

Regurgitation shortly after feeding (may then attempt to re-ingest the regurgitant)
Anorexia
Weight loss
Malnutrition
Ptyalism
Aspiration pneumonia (with associated pulmonary signs such as wheezing and crackling on lung auscultation)
Liquid food better tolerated than solid food.

Diagnostic Imaging

Fibrosing strictures must be differentiated from vascular ring anomalies, oesophagitis, intraluminal and extraluminal masses. This can be done with survey and contrast radiography, endoscopy and ultrasonography.

Survey radiographs are usually unremarkable in animals with benign oesophageal strictures. Barium contrast radiography is normally diagnostic of the disorder and may demonstrate:

Segmental or diffuse narrowing of the oesophagus
Oesphageal dilatation proximal to the site of the stricture

Ultrasonography is not usually useful in diagnosing small benign strictures but may visualise those caused by mass compression.

Oesophagoscopy is used for a definitive diagnosis. It should be used to confirm the site and severity of the stricture and also to exclude the presence of an intraluminal mass.

Treatment

The suspected cause (ie.Oesphagitis)should be corrected first. Oral feedings should be withdrawn in patients with severe stricture or oesophagitis. An oesophagostomy tube may be placed in these cases to provide nutritional support.

Medical therapies:

Oral sucralfate
Gastric acid secretory inhibitors (cimetidine, ranitidine, omeprazole)
Anti-inflammatory doses of corticosteroids (prednisolone) to prevent fibrosis and re-stricture.

Surgical therapies:

Dilation/widening of the stricture by ballooning or bougienage.
Surgical resection is not recommended because iatrogenic strictures at the anastomotic site are possible.

Prognosis

The shorter the length of oesophagus involved and the quicker the corrective procedure is performed the better the prognosis. Animals with large, mature strictures and those with continued oesophagitis have a guarded prognosis. Long term gastrostomy tubes may be required in some cases.

References

Hall, E.J, Simpson, J.W. and Williams, D.A. (2005) BSAVA Manual of Canine and Feline Gastroenterology (2nd Edition) BSAVA

Merck & Co (2008) The Merck Veterinary Manual

Nelson, R.W. and Couto, C.G. (2009) Small Animal Internal Medicine (Fourth Edition) Mosby Elsevier.

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-{{OpenPagesTop}}
+{{unfinished}}
-==Introduction==
+==Typical Signalment==
-A hiatal hernia is an abnormality of the diaphragm that allows part of the stomach and the abdominal oesophagus to displace into the thoracic cavity.  Two types of hiatal hernia have been recognised in the dog and cat:
+*Sharpei dogs are predisposed to this disorder.
-:'''Sliding hiatal hernia''' (type I) - Cranial displacement of the distal oesophagus and stomach into the mediastinum through the oesophageal hiatus of the diaphragm.  This is the most common form and it can occur in the dog and cat as a congenital or acquired lesion. Congenital hernias result from the incomplete fusion of the ''septum transversum'' (which forms the diaphragm) during early embryonic development.
-:'''Para-oesophageal''' or '''Rolling hiatal hernia''' (type II) - Cranial displacement of the gastric fundus into mediastinum through the oesophageal hiatus but adjacent to the oesophagus and gastric cardia which remain in their normal positions.  This form of hernia is rare in animals.
-==Signalment==
+==Description==
+A hiatal hernia is a diaphragmatic abnormality that allows part of the stomach and the abdominal oesophagus to prolapse into the thoracic cavity.
+Two types of hiatal hernia have been recognized in the dog and cat:
-'''Acquired''' hernias can occur in any breed of dog or cat and these often occur with disorders that cause increases in intra-abdominal pressure (such as chronic vomiting) or decreases in intrathoracic pressure (such as intermittent airway obstruction seen with [[Laryngeal Paralysis|laryngeal paralysis]] and [[Brachycephalic Airway Syndrome|brachycephalic obstructive airway syndrome]] (BOAS)).
+*'''Sliding hiatal hernia''' - Cranial displacement of the distal oesophagus and stomach into mediastinum through the oesophageal hiatus.
-Breeds of dog that develop '''congenital''' sliding hernias include Chinese Shar-peis and Chow-chows whereas brachycephalic dogs (such as English and French bulldogs) often develop acquired hernias.
+*'''Para-oesophageal hiatal hernia''' - Cranial displacement of part of the stomach into mediastinum through a defect ''adjacent'' to the oesophageal hiatus
+An oesophageal stricture is an abnormal circumferential narrowing of the lumen secondary to severe oesophagitis. A deep wall injury results followed by healing by fibrosis. The most important causes are:
+*Chemical injury from swallowed substances
+*Gastro-oesophageal reflux
+*Foreign bodies
+*Oesophageal surgery
+*Neoplasia
+*Oesophageal abscesses
 ==Diagnosis==
 ===Clinical Signs===
-Some animals may be asymptomatic but otherwise clinical signs include:
+Depend on the severity and extent of the stricture but include:
+*Regurgitation shortly after feeding (may then attempt to re-ingest the regurgitant)
+*Anorexia
+*Weight loss
+*Malnutrition
+*Ptyalism
+*Aspiration pneumonia (with associated pulmonary signs such as wheezing and crackling on lung auscultation)
+*Liquid food better tolerated than solid food.
-'''Regurgitation''' due to impaired function of the herniated lower oesophageal sphincter
+===Diagnostic Imaging===
+Fibrosing strictures must be differentiated from vascular ring anomalies, oesophagitis, intraluminal and extraluminal masses. This can be done with survey and contrast radiography, endoscopy and ultrasonography.
-'''Hypersalivation''' related to regurgitation
+Survey radiographs are usually unremarkable in animals with benign oesophageal strictures. Barium contrast radiography is normally diagnostic of the disorder and may demonstrate:
+*Segmental or diffuse narrowing of the oesophagus
+*Oesphageal dilatation proximal to the site of the stricture
-'''Dyspnoea''' and '''coughing''' if the hernia is large and impinges on the lungs or if the animal develops aspiration pneumonia as a result of regurgitation
+Ultrasonography is not usually useful in diagnosing small benign strictures but may visualise those caused by mass compression.
-'''Dehydration''' and '''weight loss''' due to chronic regurgitation
+Oesophagoscopy is used for a definitive diagnosis. It should be used to confirm the site and severity of the stricture and also to exclude the presence of an intraluminal mass.
-===Diagnostic Imaging===
-'''Plain survey radiographs''' may show a gas-filled soft tissue opacity in the caudodorsal thorax, continuous with the diaphragmatic margin.  Secondary [[Megaoesophagus|megaoesophagus]] may develop in longstanding cases and an alveolar lung pattern may be apparent, especially cranio-ventrally, if the animal is developing aspiration pneumonia.  '''Barium contrast studies''' may be used to confirm a diagnosis.  Intermittent hiatal hernias can be difficult to detect and therefore it is sometimes necessary to put pressure on the abdomen during radiography to induce displacement of the stomach.
-'''Fluoroscopy''' can be used to identify cases of intermittent herniation if the condition is still suspected after plain radiography.
-'''Endoscopy''' may demonstrate cranial displacement of the lower oesophageal sphincter and a large oesophageal hiatus.
 ==Treatment==
-If the hernia is acquired, the underlying cause should be treated.
-===Medical Management===
+The suspected cause (ie.Oesphagitis)should be corrected first.
+Oral feedings should be withdrawn in patients with severe stricture or oesophagitis. An oesophagostomy tube may be placed in these cases to provide nutritional support.
-Medical management should be initiated to reduce [[Oesophagitis|oesophagitis]] caused by regurgitation.  Medical management can be continued for cases with acquired hernias and it may achieve success in some cases with congenital hernias.  This approach involves the use of:
+Medical therapies:
-:'''[[Gastroprotective Drugs]]''' including oral sucralfate suspensions and gastric acid secretory inhibitors such as cimetidine, ranitidine or omeprazole.
+*Oral sucralfate
-:A '''low fat diet''' fed from a height will increase the tone of the lower oesophageal sphincter and increase the speed of gastric emptying, reducing the likelihood of regurgitation.
+*Gastric acid secretory inhibitors (cimetidine, ranitidine, omeprazole)
-:'''Metaclopramide''' may also be used to increase the tone of the lower oesophageal sphincter.
+*Anti-inflammatory doses of corticosteroids (prednisolone) to prevent fibrosis and re-stricture.
-:'''Antibiotics, nebulisation and coupage''' may be used to manage aspiration pneumonia.
-===Surgical Management===
+Surgical therapies:
-Surgical management can be used with congenital cases (after medical management has been attempted) and to treat the underlying cause in acquired cases.
+*Dilation/widening of the stricture by ballooning or bougienage.
+*Surgical resection is not recommended because iatrogenic strictures at the anastomotic site are possible.
-'''Hernia repair''' is achieved via a cranial ventral coeliotomy.  The oesophageal hiatus is exposed by transection of left triangular ligament (between the liver and diaphragm) and retraction of the liver.  The phreno-oesophageal ligament is partially incised and the oesophagus is retracted into the abdomen until the lower oesopageal sphincter is identified.  Sutures are then placed to reduce the size of the oesophageal hiatus.   An '''oesophagopexy''' may also be performed (tacking the oesophagus to the left body wall) or a '''fundic gastropexy'''.  A tube gastropexy has the added advantage of allowing cases to be fed if they are suffering from severe [[Oesophagitis|oesophagitis]] or oesophageal ulceration, and also allowing for decompression of the stomach in the early postoperative period..
-'''Laryngeal surgery or correction of BOAS''' may be performed if this has contributed to the hernia.
 ==Prognosis==
-Prognosis is good after surgical repair or aggressive medical management, but complete relief of clinical signs may not be possible.
+The shorter the length of oesophagus involved and the quicker the corrective procedure is performed the better the prognosis.
+Animals with large, mature strictures and those with continued oesophagitis have a guarded prognosis. Long term gastrostomy tubes may be required in some cases.
-{{Learning
-|Vetstream = [https://www.vetstream.com/canis/Content/Disease/dis00644.asp, Hiatal hernia]<br>[https://www.vetstream.com/canis/Content/Illustration/ill00366.asp, Hiatal hernia - barium contrast]<br>[https://www.vetstream.com/canis/Content/Illustration/ill00365.asp, Hiatal hernia - radiograph]
-|flashcards = [[Small Animal Soft Tissue Surgery Q&A 14]]
-|literature search = [http://www.cabdirect.org/search.html?rowId=1&options1=AND&q1=Hiatal+&occuring1=title&rowId=2&options2=AND&q2=Hernia&occuring2=title&rowId=3&options3=AND&q3=&occuring3=freetext&x=55&y=10&publishedstart=yyyy&publishedend=yyyy&calendarInput=yyyy-mm-dd&la=any&it=any&show=all Hiatal Hernia publications]
-}}
 ==References==
-Fossum, T. W. et. al. (2007) '''Small Animal Surgery''' (Third Edition) ''Mosby Elsevier''
-Hall, E.J, Simpson, J.W. and Williams, D.A. (2005) '''BSAVA Manual of Canine and Feline Gastroenterology (2nd Edition)''' ''BSAVA''
-Nelson, R.W. and Couto, C.G. (2009) '''Small Animal Internal Medicine (Fourth Edition)''' ''Mosby Elsevier''
-{{review}}
-{{OpenPages}}
+*Hall, E.J, Simpson, J.W. and Williams, D.A. (2005) '''BSAVA Manual of Canine and Feline Gastroenterology (2nd Edition)''' ''BSAVA''
-[[Category:Oesophagus_-_Pathology]]
+*Merck & Co (2008) '''The Merck Veterinary Manual'''
-[[Category:Oesophageal Diseases - Cat]][[Category:Peritoneal Cavity Diseases - Cat]][[Category:Peritoneal Cavity Diseases - Dog]][[Category:Oesophageal Diseases - Dog]]
-[[Category:Expert_Review - Small Animal]]
-[[Category:Peritoneal_Cavity_-_Developmental_Pathology]]
-[[Category:Muscles - Developmental Pathology]]
-[https://www.vetstream.com/canis/Content/Disease/dis00644.asp]
+*Nelson, R.W. and Couto, C.G. (2009) '''Small Animal Internal Medicine (Fourth Edition)''' ''Mosby Elsevier''.