Excision of Lateral Canthal Choristoma

Choristomas come in all shapes and sizes.  Unless the lesion is affecting visual development, I usually will delay surgery until after the age of two.  Often, there are other associated abnormalities.  In this case, a lateral canthal choristoma is noted with an associated lipodermoid.  Excision can be performed to give an excellent functional and cosmetic result. 

 This is Richard Allen at oculosurg.com.  This video demonstrates excision of a lateral canthal choristoma.  External photograph shows the choristoma on the lateral lower eyelid involving the lateral canthus.  There is also an associated lipodermoid.  A 15 blade is used to make an incision along the junction of the choristoma with the normal portion of the lower eyelid and lateral canthus.  This is performed 360 degrees around the choristoma.  The adjacent normal skin is preserved.  Excision of the chroistoma can then be completed with Westcott scissors.  Examination of the area shows that the lateral lower eyelid attachment will need to be reestablished.  A lower cantholysis is performed with the needle tip cautery.  Westcott scissors are then used to make a subconjunctival incision from the lateral canthal incision between the conjunctiva and the underlying lipodermoid.  Care is taken not to take this dissection too superiorly to avoid damage to the lacrimal gland ductules.  In addition, care should be taken not to damage the adjacent lateral rectus muscle.  My goal in excision of lipodermoids is to remove the visible portion of the lesion.  Complete excision may compromise the lacrimal gland ductules or cause strabismus.  Inspection shows that the visible portion of the lipodermoid has been removed.  Reconstruction will mostly be centered on placing the lateral lower eyelid in appropriate position.  This will be accomplished with a lateral tarsal strip.  Dissection is carried out between the anterior and posterior lamella.  The mucocutaneous junction of the strip is excised.  A 4-0 Vicryl suture is then placed through the periosteum of the lateral orbital rim.  This placed back hand as this is a single-armed suture.  The suture then engages the lateral tarsal strip in a mattress fashion.  The suture is then again placed through the periosteum of the lateral orbital rim to place the lateral tarsal strip in a posterior and superior position.  Tightening the suture shows some imbrication of the upper eyelid over the lower eyelid.  Therefore, a 5-0 Vicryl suture is placed to associate the lateral upper and lower eyelid prior to tying the lateral tarsal strip suture.  Interrupted 5-0 fast absorbing sutures are then placed to repair the skin defect at the lateral canthus.  Follow up photos at four months shows the lateral canthus to be in excellent position with a healing scar at the lateral canthus.