overall prognosis than surgery, since seeding of
the site is less likely and a bloodless surgical field
can be achieved.
• Diode lasers are just as effective as the CO2-YAG
laser family of instruments and are far cheaper
and much less cumbersome.
• Laser surgical removal of selected lesions has
a success rate of up to 80% and the morbidity
is usually far less than the majority of topical
treatments.
Small, well defined tumors carry the best prognosis for
surgical excision.
• Poorly defined verrucose and mixed lesions →
rapid regrowth of a more aggressive nature.
• Regrowth is likely to occur if the mass of the tumor
is incised during surgery.
• Ligation of pedunculated lesions with elastrator
bands is effective but many still recur.
• Unsuitable around eyelid and on distal limbs due
to problems with wound closure and cosmetic
results - see picture series of sarcoid removal:
○ ○ Applying tourniquet.
○ ○ Dissecting tissues.
○ ○ Excising lump.
○ ○ Free up skin at margins.
○ ○ Approximate tissues.
○ ○ Apply mesh to defect.
○ ○ Wound before suturing.
○ ○ Sutures in place.
• Not recommended for nodular eyelid tumors as,
despite benign appearance, tend to develop deep
and extensive local infiltration.
Cryosurgery
• Case selection is critical to success - overall 20-
25% chance of total resolution.
• Failures due to uncertainty of cryonecrosis and
38
extent of tumor in tissues.
• Debulking first is not helpful since then the freeze
only freezes the blood clot!
• Indiscriminate pouring of liquid nitrogen onto
sarcoids is unacceptable.
• Isolated small defined lesions respond well.
• May be impractical.
• No evidence of cryoantigen benefit as previously
reported.
• Select lesions carefully.
• Surgically debulk large masses first.
• Tumors extending over large areas, or extensively
infiltrating surrounding skin and subcutis would
be unlikely to resolve.
• Technically complicated, requiring prolonged
GA.
• Unsuitable for eyelid tumors and tumors involving
joints.
Crude liquid nitrogen contact cryosurgery
• Unpredictable results and probably unacceptable
crude tissue destruction.
Immune-mediated (immunomodulation) therapy
• BCG cell wall extracts of varying purity are used.
• Usually successful for nodular (type A and B) and
fibroblastic lesions around the eye.
• Mechanism unclear and results limited to
individual tumors injected.
• Successive injections required over several weeks
so limited practicality and cost.
• Not currently available for use in the UK due to
worldwide manufacturing issues.
Material must be injected intralesionally only - high
risk of anaphylaxis (not if pre-med with antihistamine,
flunixin and corticosteroid).
After 2nd treatment must premedicate with
dexamethasone and flunixin before injection
• Equine Health Update •