Surgery
The cat had lost 4.4 lb (2 kg) since the initial examination and was weak. A complete blood count (CBC) and serum chemistry
profile before surgery revealed that the cat was severely anemic (packed cell volume [PCV] = 11%, reference range = 30% to
46%) and that the anemia was mildly regenerative (reticulocytes = 17,520/μl, reference range = 0 to 5,000/μl; nucleated red
blood cells = 0.1 x 103/μl, reference value = 0 x 103/μl). The anemia presented an anesthetic and surgical risk, but because of the severity of the ocular lesion and the possibility
that the anemia was due to the profuse bleeding from the mass, immediate surgery was deemed necessary.
Blood typing was performed, and the cat was given one unit of type A whole blood. Preanesthetic drugs included hydromorphone
and glycopyrrolate given subcutaneously. Anesthesia was induced with intravenous propofol and midazolam, and the cat was intubated
and anesthesia was maintained with inhalation oxygen and isoflurane. During surgery, the cat was given a constant-rate infusion
of fentanyl for analgesia.
The exenteration was performed by using a transpalpebral approach. A tarsorrhaphy was performed by using 4-0 Dermalon (Syneture),
and a No. 15 scalpel blade was used to incise the skin 5 mm from the eyelid edge in an elliptical fashion to allow for smooth
skin apposition at closure. The orbital contents were removed by dissection with tenotomy scissors, which were kept as close
to the bones of the orbit as possible. The medial and lateral orbital ligaments were transected, and the nictitating membrane
was completely removed. The dissection was continued around the eye and mass until the optic nerve was encountered. The nerve
was then transected, and the tissue was completely removed.
Figure 4
|
Meticulous hemostasis was maintained to minimize any additional blood loss. To prevent excess indentation of the orbit and
to optimize the cat's appearance after surgery, sutures were placed across the orbital rim (from rim to rim) using 4-0 Dermalon
in a continuous pattern. The subcutaneous tissue was closed with 4-0 Dexon S (Syneture) in a simple continuous pattern, and
the skin was closed with 4-0 Dermalon in a simple interrupted pattern (Figure 4). Another unit of whole blood was given during the surgery, and at surgical completion, the cat's PCV was 17%.
The cat's recovery from anesthesia was uneventful, and it was released to the owner that day. For pain management, the cat
was given oral buprenorphine (0.12 mg/kg sublingually b.i.d. for three days). A two-week postoperative reevaluation with suture
removal was scheduled.
|
Featuring Information from:
