Page 223 - BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery, 2nd Edition

BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery

R L R O L R O L
VetBooks.ir O GOJ F

Lig
D
GOJ
D C
C Lig Lig
F Lig
GOJ D
D
D D
C
F

(a) (b) (c)

R L R L R L
O SI O
O

GOJ
Lig
F
GOJ D
C
Lig D C F

F
Lig GOJ
D D
D D
C

(d) (e) (f)
Protrusion of abdominal organs through the oesophageal hiatus, viewed from the ventral aspect. (a) Normal. (b) Type I: sliding or axial.
17.6 (c) Type II: rolling or para-oesophageal. (d) Type III: combined types I and II. (e) Type IV: herniation of other organs. (f) Gastro-oesophageal
intussusception. C = cardia; D = diaphragm; F = fundus; GOJ = gastro-oesophageal junction; L = left; Lig = phrenico-oesophageal ligament;
O = oesophagus; R = right; SI = small intestine.

described as a predisposing factor for hiatal hernia. This is Congenital: Congenital hernias result from a developmental
a subtype of type I, but it has been considered as a type IV defect in the structures that normally retain these viscera
hernia. Although it has been suggested that this lesion is in situ, primarily the oesophageal hiatus and phrenico-
congenital, it is more likely that the oesophagus shortens oesophageal ligament.
secondary to reflux oesophagitis and scarring. This condi-
tion has been described in a small number of dogs (Bright Acquired: Acquired hernias may develop in a number of
et al., 1990) and may result in the permanent fixation of the different situations, although a congenital predisposition
oesophagus and cardia in the thorax. may be present (Ellison et al., 1987; Burnie et al., 1989;
Bright et al., 1990; Waldron et al., 1990; Dieringer and
Sliding/oesophageal: Sliding hiatal hernia is characterized Wolf, 1991; Van Ham and van Bree, 1992; Hardie et al.,
by axial displacement of the abdominal portion of the 1998; Pratschke et al., 1998). They may be seen in animals
oesophagus, the gastro-oesophageal junction and part of with severe upper airway obstruction (laryngeal paralysis/
the stomach through the oesophageal hiatus (Ellison et al., brachycephalic airway disease) that generate a massive
1987; Prymak et al., 1989). This type of hernia usually has a pressure gradient in an attempt to get air into their lungs,
sac formed by the stretched phrenico-oesophageal liga- and passage of the stomach through the oesophageal
ment (Merdan Dhein et al., 1980). A larger hernia may also hiatus can result. Hiatal hernia may also be identified in
contain the spleen, liver and intestine. Herniated tissues young brachycephalic dogs with gastric outflow tract
may move in and out of the thoracic cavity with changes in obstruction, and it may be difficult to determine which of
the pleuroperitoneal pressure gradient. These hernias may the lesions identified are clinically relevant. However, it is
be further divided into congenital and acquired hernias. important to note that an apparently acquired hiatal

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