Page 801 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

776 CHAPTER 4

VetBooks.ir has been attempted with limited success due to 4.104
the re-formation of a stricture at the anastomosis
site. Longitudinal oesophagotomy, including lon-
gitudinal sectioning of the scar with healing by
second-intention healing, results in a traction diver-
ticulum, which is less likely to obstruct than the
circumferential scar. Partial-thickness strictures,
which do not involve the mucosa, have been success-
fully treated by oesophagomyotomy. The lumen of
strictures following circumferential ulceration is at
its narrowest 30 days after the ulceration, and there-
after increases, and has been reported as largest at
60 days. Oesophageal dilators have been used for
bougienage dilation but have met with very limited
success in horses. The prognosis for persistent cir- Fig. 4.104 Contrast oesophagram showing a pulsion
cumferential strictures is poor, with many cases suf- diverticulum.
fering repeated episodes of choke.

OESOPHAGEAL DIVERTICULA Diagnosis
Oesophagoscopy will often reveal flattening of the
Definition/overview lumen, and food accumulating in the diverticulum
Oesophageal diverticula are pathological evagina- may be visible endoscopically. The nature of a diver-
tions of the oesophageal mucosa resulting from a ticulum can best be demonstrated with contrast
defect in the muscularis. oesophagrams, which reveal a ventral defect on the
oesophageal lumen in the case of traction diverticula
Aetiology/pathogenesis and a pathognomonic ‘hour-glass’ image in the case
Oesophageal diverticula are usually acquired lesions. of pulsion diverticula (Fig. 4.104).
Two types have been described. Traction diverticula
are the result of traction resulting from the fibrosis Management
and adhesion of perioesophageal scar tissue follow- Traction diverticula rarely cause obstruction and
ing a partial- or full-thickness wound. In addition, do not require intervention in most cases. Pulsion
they occur following the healing of a ventral oesoph- diverticula can be treated by a surgical approach to
agotomy by second intention. Pulsion diverticula the oesophagus over the diverticulum, longitudi-
form when a defect of the oesophageal muscularis nally dividing the muscle layer and either invert-
occurs. The intact oesophageal mucosa prolapses ing or resecting the prolapsed mucosa, followed by
through the defect without perforation, and subse- repairing the muscle layers. Breakdown of the repair
quently increases in size as the diverticulum becomes with recurrence is the main complication. An alter-
impacted with food. native surgical option is to convert the defect from
a pulsion to a traction diverticulum, which is then
Clinical presentation allowed to granulate. Careful feeding of soft food for
Diverticula should be suspected when the horse 4–6 weeks is advised in all cases.
presents with chronic intermittent choke, particu-
larly when out at grass, or when there is a swelling of FOREIGN BODY PENETRATIONS
the cervical neck over the oesophagus that does not AND OESOPHAGEAL FISTULA
prevent passage of a NG tube. Care must be taken
when passing a NG tube to avoid the end of the tube Definition/overview
passing into the diverticulum and perforating the Foreign bodies may cause focal perforation of the
mucosa. oesophageal mucosa, with consequences including