Surgery
The horse was prepared for a standing removal of the PEH under sedation
and local anesthesia. Prior to surgery, the gelding was administered
procaine penicillin (Propercillin 22 mg/kg bwt i.m. q. 12
h)4 and gentamicin (Gentam 6.6 mg/kg bwt i.v. q. 24
h)1 and intravenous phenylbutazone. Antimicrobial
administration continued with the same regimen for 5 days,
phenylbutazone (Nabudone 2.2 mg/kg bwt i.v q 12 h)1was administered orally every 24 hours for 5 days post-operatively.
The surgical area was clipped and surgically prepared. Mepivacaine
(Vetacaine 0.07 mg/kg bwt s.c to effect)1 was
infiltrated around the proposed surgical site. A combined fronto nasal
and maxillary bone flap incision approach was performed. The rostral
perpendicular incision was made from midline to the rostral end of the
facial crest 1 cm dorsal to the infraorbital foramen, a ventral parallel
incision was made 0.5 cm dorsal to the facial crest to the caudal aspect
of the facial crest, a perpendicular caudal incision was made from the
caudal aspect of the facial crest to approximately 0.5 cm abaxial to the
incisive notch, then a short 5 cm parallel incision starting
approximately 2 cm medial to the medial canthus of oculus dexter and
finally a caudal perpendicular line from dorsal midline to join the last
incision. The periosteum was incised to expose the underlying bone and
0.5 cm of periosteum was reflected using periosteal elevators. A Jacobs
chuck with a 2mm Steinman pin was used to create equidistant holes along
the flap edges. The exposed bone was then cut with an oscillating saw
along the outlines of the flap.
The opening created in this way allowed direct access to the
conchofrontal sinus, sphenopalatine and the maxillary sinuses, ethmoid
labyrinth and the frontomaxillary opening. A large smooth oval, mottled,
to dark green tinged mass occupying the frontal, sphenopalatine,
maxillary and choncal sinuses was visualized (Figure 3 and 4). The
hematoma was isolated from the ethmoid turbinates and surrounded mucosa
by digital dissection and removed by careful traction. The sinuses were
lavaged with sterile fluids and packed with sterile gauze bandage.
Hemorrhage was considered minor during the procedure.
The fronto-nasal maxillary bone flap was replaced. The periosteum, and
subcutaneous layers were closed with number 0-2 Glycomer
631(Byosin)5 in a simple continues pattern and the
skin was then closed using a number 1 polydioxanone
(MonoPlus)6 in a simple interrupted pattern. An
elastic, self-adhesive bandage was applied to protect the surgical
incision.
Post-operatively the horse was maintained on a 5-day course of
Phenylbutazone, procaine penicillin and gentamicin sulphate as labeled
above. The tracheotomy tube was removed 24 hours post-operatively.