Helical Rim Flap
Anatomic considerations
Authored by Thomas E. J. Hayakawa, MD, FRCS(C)
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.
The anatomy of the ascending helical rim and nasal ala have an uncanny similarity (Pribaz and Falco, Ann Plast Surg, 31:289, 1993).
The similarity in the helical rim and nasal ala from the inferior nasal view.
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 superficial 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 helical rim is supplied by the superficial temporal vessels. The contralateral rim provides a good contour match for nasal ala loss.
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 side burn is present and must be taken into consideration in flap planning and design. Generally, the hair bearing area is not used.
The helical rim is outlined with a segment and adjacent facial skin necessary to reconstruct the area of tissue loss in the recipient bed.
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 distal vessels are found and the plane deep to the vessels and fascia are found. The flap is elevated deep to the artery and vein.
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 anterior and inferior incision are made to further exposed the vascular pedicle. The flap is then lifted from anterior to posterior.
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.
The entire flap is isolated on the pedicle. The auricular defect is reconstructed by excising conchal skin and cartilage and advancing the helix anteriorly (Antia method).
Because the pedicle is so short, the microvascular anastomosis is performed to the facial vessels in the nasolabial fold (see vascular anatomy illustration above).