14.2.1 General Aspects

Unilateral mucosal advancement flap technique uses two flaps, inferior- and superior-based flap, which are classified by their location in relation to the perforation (Fig. 14‑1, Fig. 14‑2). It is easier to develop large flaps from the inferior side of the perforation margin because more usable mucosa and space for handling instruments exist in the inferior nasal cavity. Therefore, the mainstay of the perforation closure is inferior-based flap. To facilitate sufficient mobilization of an inferior flap, incision is needed to be parallel to nasal cavity at the inferior aspect of the inferior turbinate. Dissection of the mucosa at nasal floor allows a maximal mobility of the flap. When more mobility of the inferior flap is required in spite of enough dissection at the inferior nasal cavity, the incision toward the anterior part of the flap, until it reaches the hemitransfixion incision, brings an additional mobility. The blood supply of the flap extended to hemitransfixion incision is provided only from the posterior nasal cavity, forming a monopedicled advancement flap. When the flap is getting larger, the risk of a new perforation increases. Especially, a simultaneous development of this flap on both sides has a possibility of a new perforation caused by the exposure of cartilage on the anteroinferior side of the septum on both sides. ^{1 ,​ 2}

When the inferior flap cannot sufficiently cover the perforation or achieve a tension-free state at the closure site, a superior-based flap can be used. To harvest a large superior flap, the mucosal dissection is needed to be extended toward the mucoperichondrium at the undersurface of upper lateral cartilage. The mucosal dissection at the superior aspect can be more easily performed by using an open rhinoplasty approach. The simultaneous creation of bilateral superior based flap brings an interruption of the blood supply on the septal cartilage, and it can induce a new septal perforation. Therefore, a precise designing of flap size and location of incision are important factors for a successful closure of septal perforation.