Changes

==Description==  

==Description==  

An oesophageal diverticulum is a circumscribed sacculation of the wall of the oesophagus. The diverticulum may be '''congenital''' or '''acquired''' and congenital diverticula usually occur due to a defect in the muscle layers of the oesophagus through which the mucosa can herniate.  Acquired diverticula can be divided into:

An oesophageal diverticulum is a circumscribed sacculation of the wall of the oesophagus. The diverticulum may be '''congenital''' or '''acquired''' and congenital diverticula usually occur due to a defect in the muscle layers of the oesophagus through which the mucosa can herniate.  Acquired diverticula can be divided into traction and pulsion forms.

*'''Traction diverticula''' involve all of the layers of the oesophageal wall and occur when '''peri-oesophageal inflammation and fibrosis''' result in the formation of adhesions between the oesopagus and surrounding tissues, distorting the normal contours of the oesophageal wall.  They develop most commonly in the cranial and middle portions of the oesophagus.  

 

*'''Pulsion diverticula''' are similar to congenital divericula in that the mucosa herniates through an acquired defect in the outer layers of the wall.  They  may be caused by any condition that places internal radial stress on the oesophageal wall, such as increases in intraluminal oesophageal pressure.  '''[[Oesophageal Foreign Body|Foreign bodies]]''', '''[[Vascular Ring Anomalies|vascular ring anomalies]]''', '''[[Oesophageal Stricture|strictures]]''' and severe '''[[Oesophagitis|oesophagitis]]''' can all therefore lead to the development of pulsion diverticula.   

'''Traction diverticula''' involve all of the layers of the oesophageal wall and occur when '''peri-oesophageal inflammation and fibrosis''' result in the formation of adhesions between the oesopagus and surrounding tissues, distorting the normal contours of the oesophageal wall.  They develop most commonly in the cranial and middle portions of the oesophagus.  

 

'''Pulsion diverticula''' are similar to congenital divericula in that the mucosa herniates through an acquired defect in the outer layers of the wall.  They  may be caused by any condition that places internal radial stress on the oesophageal wall, such as increases in intraluminal oesophageal pressure.  '''[[Oesophageal Foreign Body|Foreign bodies]]''', '''[[Vascular Ring Anomalies|vascular ring anomalies]]''', '''[[Oesophageal Stricture|strictures]]''' and severe '''[[Oesophagitis|oesophagitis]]''' can all therefore lead to the development of pulsion diverticula.   

==Signalment==

==Signalment==

*'''Post-prandial dyspnoea''' if the sacculation impinges on the lung fields.

*'''Post-prandial dyspnoea''' if the sacculation impinges on the lung fields.

*'''Aspiraton pneumonia''' with tachypnoea, dyspnoea, pyrexia and coughing may occur with any cause of chronic regurgitation.

*'''Aspiraton pneumonia''' with tachypnoea, dyspnoea, pyrexia and coughing may occur with any cause of chronic regurgitation.

*Signs that occur if the oesophagus ruptures are described [[Rupture of the Oesophagus|here]].

Signs that occur if the oesophagus ruptures are described [[Rupture of the Oesophagus|here]].

===Diagnostic Imaging===

===Diagnostic Imaging===

Any underlying cause of an acquired diverticulum should be removed or treated where possible.  Diverticula themselves may be managed medically or surgically, depending on their size.

Any underlying cause of an acquired diverticulum should be removed or treated where possible.  Diverticula themselves may be managed medically or surgically, depending on their size.

*'''Small diverticula''' may be managed medically by feeding '''soft or liquid diets''' and '''elevating the forelimbs''' of the animal for 10-15 minutes after each meal to encourage food boluses to pass into the stomach.

*'''Small diverticula''' may be managed medically by feeding '''soft or liquid diets''' and '''elevating the forelimbs''' of the animal for 10-15 minutes after each meal to encourage food boluses to pass into the stomach.

*'''Larger diverticular''' and '''small pulsion diverticula''' should be corrected surgically as they are more likely to cause clinical signs and because pulsion diverticula may enlarge over time as food becomes impacted in the sacculation.  A '''diverticulectomy''' is performed after entering the chest cavity by a lateral thoracostomy or median sternotomy, depending on its exact location.  The diverticulum is removed and the wall of the oesophagus is sutured longitudinally to try to prevent the formation of strictures.  Since the oesophagus has no serosal layer, the repair may be augmented with muscle flaps (from the longus colli or intercostal muscles), with omentum brought into the chest cavity or with synthetic mesh.  It is important that the repair not be under tension to prevent dehiscence and a headcollar and side reins may be used post-operatively to prevent this.

*'''Larger diverticula''' and '''small pulsion diverticula''' should be corrected surgically as they are more likely to cause clinical signs and because pulsion diverticula may enlarge over time as food becomes impacted in the sacculation.  A '''diverticulectomy''' is performed after entering the chest cavity by a lateral thoracostomy or median sternotomy, depending on its exact location.  The diverticulum is removed and the wall of the oesophagus is sutured longitudinally to try to prevent the formation of strictures.  Since the oesophagus has no serosal layer, the repair may be augmented with muscle flaps (from the longus colli or intercostal muscles), with omentum brought into the chest cavity or with synthetic mesh.  It is important that the repair not be under tension to prevent dehiscence and a headcollar and side reins may be used post-operatively to prevent this.

==Prognosis==

==Prognosis==

[[Category:To_Do_-_James]]

[[Category:To_Do_-_James]]

[[Category:Dog]][[Category:Cat]]

[[Category:Dog]][[Category:Cat]]