Helical Rim Flap

Based on the Microsurgical Grand Rounds presentation by Tom Hayakawa M.D., F.R.C.S.(C.) in October 2007, CPMC, Davies Campus.

Full thickness loss of the nasal ala is difficult to reconstruct. As pointed out by Pribaz in 1993, the ascending helical rim has an uncanny resemblance to the nasal ala. It also provides skin and cartilage, as well as a comparable color match to provide for reconstruction of this very prominent area, while leaving an aesthetically pleasing donor area.

 

Vascular Anatomy

The superficial temporal vessels ascend superiorly, just anterior to the ear as the travel toward the scalp and superficial temporal fascia.  During this course, the vessels distribute numerous small branches including branches to the ascending helical rim.  The superifical temporal vessels are the basis of this flap, with the soft tissue resection capturing inflow and drainage to this flap via small branching vessels. 
The anatomy of the superficial temporal vessels can be aberrant on occasion, particularly the vein.  We have found occasion where the superficial temporal vein is not present in proximity to the artery.

The root and ascending helical rim in the adult measure approximately 3 centimeters - the maximum flap harvested.  The skin immediately anterior to the ascending helix is not hair bearing.  But as one proceeds anteriorly, the sideburn is present and must be taken into consideration in flap planning and design.  Generally, the hair bearing area is not used.

A distal incision is made to isolate the superficial temporal vessels distal to the flap.  The are be ligated and divided here unless superficial temporal fascia will be harvested.

The anterior and inferior preauricular incision are made and the flap can be elevated from anterior to posterior.  This is done deep to the superficial temporal vessels.  Since the facial nerve is quite deep anterior to the tragus, the dissection is maintained superficial to it.

The posterior incision is made through the skin and cartilage, and the helical rim cartilage is transected at the anterior fold, staying deep to the superficial temporal vessels as the dissection proceeds to join the anterior flap. 

The remaining helix superiorly is elevated as a skin, cartilage flap, leaving the posterior skin intact, as in the method of Antia.  The superior conchal cartilage (thatched area in the figure) is excised, much like a Burrows triangle.  The superior helical rim can then be advanced to the helical root, and the donor defect can be closed with fine suture.

Because the pedicle is so short, the microvascular anastomosis is performed to the facial vessels in the nasolabial fold (see vascular anatomy illustration above).