Craniofacial Muscles

308 J. Park et al.
septum should be preserved to avoid this deformity.
(g) Visible scar : Suprabrow incisions provide better visualization for corrugator
supercilii and procerus muscle removal, but a visible scar above the brow limits
its use.
(h) Hypoesthesia : Removal of the lateral corrugator muscle has a risk of supraorbital
neurovascular bundle damage and consequent hypoesthesia of the forehead.
It can recover within 1 year, but sometimes can be permanent.
(i) Dry eye , lagophthalmos , exposure keratopathy : Dry eye and exposure keratopathy
can be caused or aggravated by orbicularis myectomy as it attenuates eyelid
closure.
(j) Chronic lymphedema : Lymphedema may last for longer than 1 year until new
lymphatic channels begin to function. Upper and lower eyelid myectomy should
be staged to avoid chronic lymphedema that is caused by extensive damage to
lymphatic vessels as a result of simultaneous surgery to both upper and lower
eyelids.
(k) Irregularity of eyelid skin , periorbital contour deformity : Subcutaneous scar
tissue and long standing lymphedema can result in an irregular skin surface.
(l) Recurrence of blepharospasm : Although the resected muscles do not appear to
regenerate, blepharospasm can recur presumably due to incomplete removal of
the orbicularis oculi muscle. In such cases, BoNT injection is necessary after
the surgery. Subcutaneous fi brotic scar tissue from the surgery prevents diffusion
of BoNT and causes the injections to be more painful.
16.8.4.2 Chemomyectomy
Doxorubicin (Adriamycin), a cytotoxic anthracycline used to treat disseminated
neoplasms, is a potent method for the permanent removal of muscle via local injection
and is under investigation as a treatment of patients with BEB and HFS
(Wirtschafter and McLoon 1998 ; Wirtschafter 1991 ; Wirtschafter 1994 ) . It has a
relatively selective effect in damaging muscle fi bers by altering intracellular calcium
hemostasis. Doxorubicin opens calcium channels in internal cisternae and
activates calcium release from the sarcoplasmic reticulum. In animal experiments,
there is loss of muscle mass, which is greatest near injection sites. The drug causes
degeneration of the treated muscles and permanent muscular weakness. One favorable
outcome is a resulting “blepharoplasty” and reduced wrinkling of the eyelids
skin that is normally caused by the underlying muscle fi bers. Skin erythema and
ulceration at injection sites are frequent complications and are dose-dependent
(Wirtschafter 1994 ) .
Doxil (Sequus Pharmaceuticals, Menlo Park, CA) is a liposome-encapsulated
form of doxorubicin (Harrison 2003 ) . In monkeys, the chemomyectomy effect of
Doxil was similar to that of doxorubicin. The bene fi t of the liposome-encapsulated
form of doxorubicin was the reduced incidence of skin injury; however, its myotoxicity
and therefore its ef fi cacy were also reduced compared to doxorubicin alone
(McLoon and Wirtschafter 2001 ) .