Inferior Turbinate Flap

Indications




  • Medium (1–2 cm) and/or large (> 2 cm) size NSPs



  • NSP without osteocartilaginous support



  • Rescue flap for NSP


11.2 Contraindications




  • In any patient who has undergone sphenopalatine artery or anterior ethmoidal artery ligation on the ipsilateral side.



  • Previous inferior turbinectomy or inferior turbinate (IT) surgery may reduce the flap’s pliability, limit its ability to mold to the shape of the defect, and may also compromise its blood supply.


11.3 Anatomy


The IT bone develops from a cartilage ossification center during the fifth intrauterine month. At the core of the IT is its central osseous layer of nonhomogeneous, cancellous, sponge-like bone made of interwoven bony trabeculae separated by a labyrinth of interconnecting spaces containing fatty tissue and blood vessels. The histology of the IT is comprises an epithelial mucosal layer overlying a basement membrane, an osseous layer, and an intervening lamina propria. The medial aspect of the mucosal layer is thicker and has more surface area than the lateral mucosa of the turbinate. 1


IT is vascularized by the posterolateral nasal artery (PLNA) ( ▶ Fig. 11.1). The PLNA descends vertically and slightly forward over the vertical apophysis of the palatine bone and enters the IT on the superior aspect of its lateral attachment between 1.0 and 1.5 cm from its posterior insertion. In 15% of cases the IT may receive supplementary irrigation from the palatine artery branches of the descending palatine artery. 2 Wu et al 3 studied the vascular anatomy of the IT in 11 cadavers. They observed that mean outer diameter of the PLNA is 1.10 ± 0.11 mm (range: 0.82–1.30); and it enters the IT on the superior aspect of its lateral attachment, 1.0 to 1.5 cm from its posterior tip; and divides in 2.50 ± 0.52 (range: 2–3) arteries as part of IT circulation. After the division the arteries enter a bony canal; one branch remains high and lateral while the other runs in a lower and more medial position. Both remain in bony canals or are closely applied to the bone for much of the length of the turbinate. The lower (medial) branch gives off branches that pierce the bone of the interior turbinate in its anterior part and form a regular pattern of alternating superior and inferior branches at right angles to the main artery. As the arteries run anteriorly, they increase in size, suggesting that there is a significant additional blood flow from anteriorly. These blood supplies are from an anastomosis with the anterior ethmoidal artery and the lateral nasal artery, which is a branch of the facial artery.



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Fig. 11.1 (a) Scheme of the inferior turbinate vascularization. AEA, anterior ethmoidal artery; ANLA, anterior lateral nasal artery (branch of the facial artery); MT, middle turbinate; PLNA, posterior lateral nasal artery. (b) Endoscopic photograph of the inferior turbinate arteries. PLNA, posterior lateral nasal artery; <, superior lateral inferior turbinate artery; >, inferior medial inferior turbinate artery; *, branch of the descending palatine artery to the inferior turbinate.


The ITF presents an excellent anteroposterior distance but lacks of a wide width. Gras-Cabrerizo et al 4 studied four cadaveric specimens and showed an anteroposterior distance range between 4.2 and 5 cm, with a width range between 1.2 and 1.4 cm. Amit et al 5 obtained similar results with a mean length and width of 4.8 and 1.8 cm, respectively, in 11 cadaver specimens. Harvey et al 6 obtained a similar length (5.4 cm), but with greater width (2.2 cm) extending its dissection to the inferior meatus and/or fossa floor.


11.4 Surgical Steps


11.4.1 Sinonasal Cavity Preparation


Cottonoids impregnated with a solution of 1:10,000 epinephrine are placed in the nasal cavity bilaterally during the surgical setup. At the beginning of surgery, the sites corresponding to the planned incisions are injected with lidocaine 1% with epinephrine 1:100,000. One must avoid injecting the area adjacent to the flap’s vascular pedicle (i.e., it causes vasospasm of the pedicle potentially impairing its viability) and the interior turbinate (i.e., it may be equivalent to an intravascular injection).


11.4.2 Posteriorly Based Inferior Turbinate Flap: Surgical Technique




  1. The nasal cavity is decongested and prepared as previously described.



  2. The IT can be gently medialized to better visualize its medial surface and the mucosa from the inferior meatus, and then subsequently laterally fractured to gain access to the lateral nasal wall.



  3. An uncinectomy allows the identification of the natural ostium of the maxillary sinus and the posterior portion of the IT. In some cases enlargement of the maxillary sinus ostium posteriorly allows a better exposure of the PLNA and eases the preservation of the pedicle ( ▶ Fig. 11.2).



  4. Elevate the mucosa from the anterior aspect of the ascending process of the palatine bone in a submucoperiosteal plane and proceed posteriorly to identify the crista ethmoidalis, sphenopalatine foramen, and sphenopalatine artery and its terminal branches. The sphenopalatine foramen is identified superior to the posterior IT, posterior to the basal lamellae of the middle turbinate. The pedicle blood supply to the IT can sometimes be visualized as pulsating. There is significant anatomical variation of the sphenopalatine artery branches and, accordingly, the sphenopalatine foramen or foramina. In fact, the PLNA may extend anterior to the posterior wall of the maxillary antrum. 7,​ 8 Recognizing this anatomic variation during the maxillary antrostomy and mucoperiosteal elevation is vital to avoiding injury to the vascular pedicle.



  5. Define the superior and inferior limits of the flap.




    1. Make a posterior to anterior incision along the superior sagittal plane of the IT (superior incision).



    2. Then make an inferior sagittal incision along the inferior meatus (inferior incision); in some cases one can extend the flap to the inferior meatus and nasal floor.



  6. A vertical incision at the head of the IT then connects the two incisions (anterior incision). This incision is in S-shape, starting from the superior incision and sloping around the contour of the head of the IT and onto the inferior meatus. Care should be taken to avoid disrupting the valve of Hasner.



  7. Use a periosteal elevator (freer dissector or Cottle elevator) to raise the mucoperiosteum off the IT from anterior to posterior both medial and lateral to the IT bone. The donor site is left open and allowed to heal, which is frequently the case after partial turbinectomy.



  8. After harvesting the flap, margins of the perforation are easily elevated and/or rimmed with a 12-blade or a phaco blade. The two mucosal layers surrounding the perforation edges are separated from each other at least 3 to 4 mm in width circumferentially.



  9. Finally the edges are sutured with absorbable suture (i.e., 2–0 Vicryl). Usually anterior, middle, and posterior sutures are placed to achieve complete closure. Sometimes the posterior sutures are difficult to place and they are reserve for the second surgery when the pedicle is detached from the lateral wall.



  10. Second stage: After 6 weeks to 6 months, the pedicle is detached from the lateral nasal wall; bipolar cautery is used for hemostasis. The pedicle is transacted and the excess pedicle is discarded. At 3 weeks after surgery, the contralateral side of the flap has usually reepithelialized. Patients are instructed to keep the sides moist with nasal saline spray during the 3-week period.



978-3-13-205391-5_c011_f002.eps


Fig. 11.2 Posteriorly based inferior turbinate flap (pITF). Schematic drawing showing the incision to raise a pITF. Care must be taken when performing the posterior incision as the PLNA runs just anteriorly to the place where the posterior incision is made. MT, middle turbinate; PLNA, posterior lateral nasal artery; a, superior incision; b, inferior incision; c, anterior incision; d posterior incision.


11.4.3 Anteriorly Based Inferior Turbinate Flap




  1. Repeat steps (1–5) of the PITF.



  2. Because the pedicle of this flap is based anteriorly, care is taken not to injure the branches of the AEA, which passes anterior to the agger nasi. These branches arc below the nasal bone and spine of the frontal bone in a C-shaped loop before entering the IT.



  3. Cauterization of the PLNA with bipolar/monopolar cautery or clips can be used.



  4. Prolong the posterior incision through the tail of the IT in front of the eustachian tube and below to the inferior meatus. This step is crucial to free the posterior margin of the flap.



  5. The entire portion of the IT is usually harvested.



  6. Next, the mucoperiosteum covering the turbinate is elevated in an anterior to posterior direction with the use of a Cottle elevator and endoscopic scissors. The flap includes the entire mucosa of the IT, and it is detached from its inferior and lateral attachments ( ▶ Fig. 11.3).



  7. Finally the AITF is based anteriorly and vascularized by the AEA and branches of the anterolateral nasal artery (ALNA) ( ▶ Fig. 11.4).



  8. After harvesting the flap, margins of the perforation are easily elevated and/or rimmed with a 12-blade or a phaco blade. The two mucosal layers surrounding the perforation edges are separated from each other at least 3 to 4 mm in width circumferentially.



  9. Finally the edges are sutured with absorbable suture (i.e., 2–0 Vicryl). Usually anterior, middle, and posterior sutures are placed to achieve complete closure. Sometimes the posterior sutures are difficult to place and they are reserve for the second surgery when the pedicle is detached from the lateral wall.



  10. After 6 weeks to 6 months, the pedicle is detached from the lateral nasal wall; bipolar cautery is used for hemostasis. The pedicle is transacted and the excess pedicle is discarded. At 3 weeks after surgery, the contralateral side of the flap has usually reepithelialized. Patients are instructed to keep the sides moist with nasal saline spray during the 3-week period.



978-3-13-205391-5_c011_f003.eps


Fig. 11.3 Anteriorly based inferior turbinate flap (aITF). Schematic drawing showing the incision to raise an aITF. AEA, anterior ethmoidal artery; ANLA, anterior lateral nasal artery (branch of the facial artery); PLNA, posterior lateral nasal artery; a, superior incision; b, inferior incision; c, posterior incision; *, clipping or cauterization of PLNA.

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Nov 27, 2018 | Posted by in OTOLARYNGOLOGY | Comments Off on Inferior Turbinate Flap
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