Page 658 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Respir atory system: 3.2 Surgical conditions of the respir atory tr act 633

VetBooks.ir sternothyroid muscle onto the thyroid cartilage of of the palate preceded DDSP (Fig. 3.66), surgi-
Following treadmill observation that billowing
the larynx – the Llewellyn procedure. This can be
combined with a laryngotomy at which some sur-
Thermal palatoplasty – either photocautery using
geons perform a staphylectomy. A staphylectomy cal techniques to stiffen the palate were developed.
is a resection of tissue from the free border of the a laser, or actual cautery using red hot irons – has
soft palate, performed via a laryngotomy, and has had considerable interest (Fig. 3.69). The technique
been a widely used surgical technique. It was based (particularly actual cautery) is simple to conduct and
on the discredited concept of intermittent DDSP should produce the goal of stiffening the soft palate.
being due to an elongated soft palate. 2–3 cm of tis- Treated horses are able to return to exercise rapidly,
sue is surgically removed from the free border of the after only approximately 2 weeks of rest. The pub-
soft palate via a laryngotomy. Some horses develop lished results do not appear to be better than any
dysphagia associated with excessive shortening of other surgery.
the soft palate (Fig. 3.68). Dynamic endoscopy
shows that horses that have had a staphylectomy Prognosis
do develop DDSP at exercise very easily, but this The prognosis for almost all procedure used to treat
is associated with less respiratory obstruction than DDSP is 60%. Various studies of the procedures
might be the case with non-treated horses, probably available show comparable success rates, between
because of the reduction of the bulk of tissue avail- 50% and 70%. A systematic review of the literature
able to cause an obstruction. Other procedures that has been published, but it largely highlighted the
have been performed during a laryngotomy include many variables associated with racing performance,
ventriculectomy and cordectomy and subepiglottic which make it difficult to draw firm conclusions on
resection. the efficacy of the procedures.

3.68 3.69

Fig. 3.68 A horse that has undergone a Fig. 3.69 The soft palate of a horse following
ventriculectomy or Hobday procedure, as well as a thermal palatoplasty by actual cautery.
staphylectomy, which has resulted in permanent dorsal
displacement of the soft palate and dysphagia.