Page 125 - BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery, 2nd Edition

Chapter 9
VetBooks.ir

Surgery of the oesophagus

Jennifer Huck and Andrew E. Kyles

Introduction characteristic ‘herringbone’ appearance of the feline caudal
thoracic oesophagus on positive-contrast oesophagogram.
Oesophageal surgery is performed infrequently in dogs The blood supply to the oesophagus is considered
and cats, although there are a number of well defined indi- to be segmental. The arterial supply originates from the
cations. Surgery on the oesophagus has been associated cranial and caudal thyroid, broncho-oesophageal, intercos-
with a higher prevalence of incisional dehiscence than tal, diaphragmatic and left gastric arteries. A rich intramural
surgery on other portions of the alimentary tract, however, plexus of anastomosing vessels exists in the submucosal
it can be successfully performed by adhering to certain layer and can support long segments of the oesophagus.
surgical principles. Branches of the vagal nerves are closely associated
with the oesophagus from the level of the heart caudally.

Functional anatomy
Surgical approaches
The oesophagus is a muscular tube that functions as a
conduit between the pharynx and stomach, with functional The cervical portion of the oesophagus is approached by
sphincters at the pharyngo-oesophageal and gastro- a ventral midline cervical incision, separating the paired
oesophageal junctions. The ‘upper’ oesophageal sphincter sternohyoid muscles and retracting the trachea to the
comprises the cricopharyngeus muscle and circular right. Care should be taken to avoid damage to the left
muscle fibres of the proximal oesophageal wall. The cervi- recurrent laryngeal nerve during tracheal retraction. This
cal portion of the oesophagus begins dorsal to the cranial approach can be extended via a cranial median stern-
trachea and, as the oesophagus runs caudally, inclines to otomy to expose the cranial thoracic oesophagus to the
the left of the trachea. The cervical oesophagus is closely level of the tracheal bifurcation.
associated with the left carotid sheath and left recurrent The cranial thoracic portion of the oesophagus can also
laryngeal nerve. The thoracic portion of the oesophagus be exposed via a left third or fourth, or a right third, fourth or
inclines dorsally in the cranial mediastinum to return to its fifth intercostal thoracotomy. During a left-sided approach,
position dorsal to the trachea at the level of the tracheal the oesophagus is exposed by ventral retraction of the
bifurcation. The oesophagus passes to the right of the brachiocephalic trunk and subclavian vessels. On the right
aortic arch, and runs through the caudal mediastinum to side, the oesophagus is exposed by ventral retraction of the
the oesophageal hiatus of the diaphragm. The ‘lower’ trachea, which can be combined with retraction or ligation
oesophageal sphincter acts as a high-pressure zone with of the azygos vein to increase the exposure of the oesoph-
contributions from the diaphragmatic crural muscles agus at the base of the heart.
and folds of the gastro-oesophageal mucosa. The short The caudal thoracic portion of the oesophagus is usually
abdominal portion of the oesophagus begins at the oeso- approached via a left-sided seventh, eighth or ninth inter-
phageal hiatus and ends at the cardia of the stomach. costal thoracotomy in order to avoid the caudal vena cava.
The oesophageal wall consists of four layers: mucosa; The dorsal and ventral vagal nerves should be identified and
submucosa; muscularis; and adventitia. The adventitia of preserved. The caudal oesophagus and stomach can be
the oesophagus blends readily with the fascia of other approached by a combined ventral midline laparotomy and
surrounding structures. diaphragmatic incision, or caudal median sternotomy.

• In dogs, the muscularis layer consists of two obliquely
positioned layers of striated muscle throughout the Principles of oesophageal
length of the oesophagus, and there are distinct
longitudinal folds in the mucosa. surgery
• In cats, the muscularis layer consists of striated muscle
cranial to the heart and smooth muscle caudal to the When performing oesophageal surgery, the chance of a
heart. There is an abrupt change in the mucosal successful outcome can be increased by adhering to
pattern at the level of the heart base. certain surgical principles, including:

The longitudinal mucosal folds continue and distinct trans- • Gentle tissue handling to prevent damage to the
verse mucosal folds are superimposed. This results in the intramural blood supply

116 BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery, second edition. Edited by Daniel J. Brockman, David E. Holt and Gert ter Haar. ©BSAVA 2018

Ch09 HNT.indd 116 31/08/2018 11:36