Transnasal Endoscopic Medial Maxillary Sinus Wall Transposition With Preservation of Structures

The Laryngoscope VC 2015 The American Laryngological, Rhinological and Otological Society, Inc. Transnasal Endoscopic Medial Maxillary Sinus Wall Transposition With Preservation of Structures Alice Z. Maxfield, MD; Tiffany T. Chen, MD; Tiago F. Scopel, MD; Robert Engle, MD; Kristina Piastro, MD; Anna Butrymowicz, MD; Tyler Kenning, MD; Carlos D. Pinheiro-Neto, MD, PhD Objectives/Hypothesis: To evaluate the increase in access to the maxillary sinus (MS) with transnasal endoscopic medial maxillary sinus wall transposition (TEMMT), while preserving major structures of the nasal cavity. Study Design: The study was divided into three parts: anatomical, radiographic, and case series. Methods: Three cadaveric dissections (total of six sides) confirmed the feasibility of the TEMMT approach. Radiographic measurements using maxillofacial computed tomography scans were taken to assess the maximal antrostomy. The TEMMT approach was performed on six consecutive patients with benign MS disease. Results: The cadaveric measurements were consistent with the radiographic measurements, which confirmed the maximum access to the MS. The radiographic measurements ranged from 14.4 to 39.1 mm in the anteroposterior dimension, 8.2 to 23.7 mm in the superior-inferior dimension, and 368 to 988 in the angle between the medial and anterior wall of the MS. In the patient series, five patients presented with an odontogenic cyst, and one patient had an antrochoanal polyp in the MS. The TEMMT approach provided excellent access and adequate resection, as well as preservation of the nasolacrimal duct and inferior turbinate. Finally, the mucosal flap was sufficient to cover the inferior meatal antrostomy. Conclusions: TEMMT provides excellent access into the MS, especially the floor and anterior wall, without the morbidities of the Caldwell-Luc or medial maxillectomy approach. In addition, the transposition of the inferior turbinate and the mucosal flap provides coverage of the medial wall with preservation of the inferior meatus, inferior turbinate, and nasolacrimal duct for patients with benign MS disease. Key Words: Maxillary sinus, transnasal endoscopic medial maxillectomy, inferior turbinate, nasolacrimal duct. Level of Evidence: NA Laryngoscope, 126:1504 1509, 2016 INTRODUCTION Endoscopic sinus surgery has revolutionized the management of both benign and malignant sinus disease. Open approaches for medial maxillectomy, such as lateral rhinotomy and midface degloving, provide good access to the maxillary sinus (MS); however, they are plagued with high morbidity. Complications of medial maxillectomy have been reported to be up to 30%, including epiphora, dacryocystitis, diplopia, mucocele, cerebrospinal fluid leak, epistaxis, and external scarring. 1 Since the advancement in powered instruments and visualization with angled scopes, endoscopic management of benign sinus disease has become the standard of From the Division of Otolaryngology, Department of Surgery (A.Z.M., T.T.C., T.F.S., R.E., K.P., A.B., C.D.P.-N.), Albany Medical Center, Albany, New York; and the Department of Neurosurgery (T.K.), Albany Medical Center, Albany, New York, U.S.A. Editor s Note: This Manuscript was accepted for publication November 20, 2015. Presented at the North American Skull Base Society Annual Meeting, Tampa, Florida, U.S.A., February 20 22, 2015. The authors have no funding, financial relationships, or conflicts of interest to disclose. Send correspondence to Carlos D. Pinheiro-Neto, Albany Medical Center, Division of Otolaryngology, 50 New Scotland Ave., Fourth Floor, Albany, NY 12208. E-mail: pinheic@mail.amc.edu DOI: 10.1002/lary.25832 1504 care. Certain benign sinus diseases, such as inverted papilloma, have been managed with a combined Caldwell-Luc and endoscopic approach to decrease the recurrence rate. The Caldwell-Luc approach provides an anterior direct approach to the MS; however, it still carries the morbidity of a gingival buccal sulcus incision. The endoscopic medial maxillectomy approach, with preservation of the medial buttress, inferior turbinate, and nasolacrimal duct offers wide access to the MS, especially useful for nasal irrigation and application of medical therapy. Preserving the nasolacrimal duct and inferior turbinate decreases the incidence of epiphora and atrophic rhinitis, maintaining normal airway turbulence and humidification. 2 However, a large maxillary antrostomy may result in permanent drying and disruption in mucociliary clearance. Previous open and endoscopic approaches deliver acceptable results for the management of benign sinonasal disease, but nevertheless carry significant morbidity. Therefore, we propose the transnasal endoscopic medial maxillary sinus wall transposition (TEMMT) approach as an alternative for benign disease to decrease morbidity by preserving the inferior turbinate, inferior meatus, and nasolacrimal duct, while also maintaining nasal mucosa and restoring the normal drainage pathway to uphold anatomy and sinonasal drainage physiology.

Fig. 1. Cadaveric dissection showing the steps of the transnasal endoscopic medial MS wall transposition approach on the left side. (A D) Pictures obtained with a 08 endoscope. (E F) Pictures obtained with a 308 endoscopes. (A) Incision at the head of the IT. (B) Medialization of the IT to show the inferior meatus. (C) Incision in the nasal cavity floor mucosa and elevation of the meatal flap. (D) Exposure of the bone of the medial MS wall. (E) View after drilling the MS wall and exposure of the sinus. (F) A 308 endoscopic view of the anterior wall of the maxillary sinus. IT 5 inferior turbinate, MS 5 maxillary sinus. MATERIALS AND METHODS The study was divided into three parts: anatomical, radiographic, and case series. Three cadaveric dissections (total of six sides) were completed to confirm the feasibility of the TEMMT approach. The procedure was then performed in six consecutive patients with benign MS disease. The Surgical Approach The TEMMT procedure was performed under general anesthesia. Surgical pledgets soaked in oxymetazoline were applied to the nasal cavity to decongest the mucosa. In both cadaveric dissections and surgical patients, we started the approach by making a vertical incision at the head of the inferior turbinate (IT) using endoscopic scissors (Fig. 1A). This allowed upward mobilization of the IT and exposure of the inferior meatus (Fig. 1B). Needle tip bovie electrocautery was used to make an incision from the tail of the IT to the septum, crossing the floor of the nasal cavity and extending about 5 mm up the septum to include a strip of septal mucosa. Then, the incision was carried anteriorly in the sagittal plane up to the level of the anterior nasal spine. Finally, an incision was made from the septum, crossing the nasal floor to the head of the IT, at the mucocutaneous junction of the nostril. Using a Cottle elevator, the nasal cavity floor mucosa was elevated, allowing exposure of the nasal floor (Fig. 1C). The dissection was progressed laterally with elevation of the meatal mucosa and exposure of the wall of the inferior meatus. The elevation of the mucosa was performed up to the insertion of the inferior turbinate, displacing the flap upward together with the inferior turbinate. A drill was used to enter the MS through its medial wall at the inferior meatus (Fig. 1D). In the surgical patients, the limits of the opening were tailored accordingly to the disease process. An image-guidance system (Brainlab, Feldkirchen, Germany) was used in all patient cases. The anterior limit was the anterior MS wall; care was taken to avoid entry into the soft tissue of the cheek (Fig. 1E,F). The posterior limit was the greater palatine canal or the extent needed for full access to the disease process. Once the resection was completed, the mucosal flap was replaced and the IT lateralized, covering the medial maxillary wall defect and restoring the inferior meatus. Care was taken 1505

six patients in the case series. All imaging was reviewed: 26 scans used 1.25-mm axial cuts, one was 0.6 mm, two were 1.0 mm, two were 2.0 mm, three were 2.5 mm, two were 3.0 mm, and two scans did not have axial cuts. Two patients did not have axial images, only coronal. Coronal reconstruction was generated from the axial images; however, two patients did not have coronal images. CT scans of patients with trauma and/or tumors involving the area of interest were excluded. Measurements were taken using the ruler application in our electronic imaging database (isite Enterprise; Koninklijke Philips N.V., Amsterdam, the Netherlands). Using the axial view, measurements of the anteriorposterior distance of the bilateral MS were taken at the most inferior level with full length of the IT (Fig. 2A). At this same level, the angle formed by the medial and anterior wall of the MS was measured bilaterally (Fig. 2A). Coronal views were used for the measurement of the maximal height of the MS wall at the inferior meatus (Fig. 2B). The measurement was taken from the attachment of the IT to the medial MS wall superiorly to the nasal floor inferiorly. This corresponded to the maximum height that could be accessed through the inferior meatus. Case Series Six consecutive patients with benign disease involving the anterior wall and/or the floor of the MS underwent TEMMT. There were four male and two female patients, with an average age of 56 years (minimum: 51, maximum: 64). Fig. 2. Radiographic measurements. (A) CT scan showing the most inferior axial cut with the full length of the IT. Measurements are taken of the AP dimension of the MS at the inferior meatus and the angle formed by the medial and anterior wall of the MS. (B) CT scan showing the maximum height between the attachment of the IT and the nasal cavity floor. AP 5 anterior-posterior; CT 5 computed tomography; IT 5 inferior turbinate; MS 5 maxillary sinus. to preserve the largest mucosal flap possible by incising at the mucocutaneous junction to ensure complete closure of the opening, as the mucosal flap will shrink slightly. A standard middle meatus maxillary antrostomy was also performed in all cases. Nasal splints were used in all cases. No nasal packing was used. Cadaveric Dissection In the cadaveric study, the dissections performed followed the same steps of the surgical procedure (Fig. 1). The anterior limit was the anterior wall of the MS. All the work in the inferior meatus and MS was performed inferior to the opening of the nasolacrimal duct. The superior limit was the attachment of the superior aspect of the IT to the medial MS wall. The posterior limit was the descending palatine artery canal at the greater palatine canal and the posterior wall of the MS. The anterior-posterior and superior-inferior dimensions of the maxillectomy were measured using a ruler. A total of three adult human cadaver specimens (six sides) were dissected using the TEMMT surgical approach: two female, one male. Radiologic Study Maxillofacial computed tomography (CT) scans of 38 patients were studied: 22 males, 16 females. The mean age was 40.8 years (range, 17 76 years). This included imaging from the Statistical Analysis Data were analyzed using Microsoft Excel) version 14.1.4 for Macintosh (Microsoft Corp., Redmond, WA). Minimum, maximum, mean, and standard deviation were calculated. RESULTS In all six cadaveric dissections, the inferior meatal flap was easily elevated and the anterior and lateral walls of the MS were accessible with the TEMMT approach. Using the 08 and 308 endoscopes, the anterior and lateral walls of the MS were easily visible. At the end, the flap was sufficient to cover the medial maxillectomy defect with some shrinkage of the flap. Cadaveric measurements of maximal medial maxillary wall antrostomy at the inferior meatus are shown in Table I. TABLE I. Cadaveric Dissection Measurements of the Maximal Maxillary Sinus Opening. Cadaver Sex Anterior-Posterior (mm) Height (mm) Specimen 1 Right Female 22 17 Specimen 1 Left 20 18 Specimen 2 Right Female 25 22 Specimen 2 Left 20 15 Specimen 3 Right Male 35 25 Specimen 3 Left 33 21 Mean 25.8 19.7 1506

TABLE II. Radiologic Measurements of the Maxillary Sinus From Computed Tomography Imaging of 38 Patients. AP (R) AP (L) AP (R&L) Height (R) Height (L) Height (R&L) Minimum (mm) 17.2 14.4 14.4 11.4 8.2 8.2 Maximum (mm) 39.1 36.6 39.1 23.7 23.2 23.7 Mean 6 SD (mm) 25.7 6 5.3 26.0 6 6.0 25.8 6 5.6 17.8 6 3.3 17.6 6 3.6 17.7 6 3.4 Angle (R) Angle (L) Angle (R&L) Minimum (8) 39 36 36 Maximum (8) 98 90 98 Mean 6 SD (8) 65.1 6 13.0 62.5 6 12.3 63.8 6 12.6 AP 5 anterior-posterior; L 5 left; R 5 right; SD 5 standard deviation. Radiologic measurements of the MS from CT imaging are shown in Table II. The measurements of the anterior-posterior dimension and the superior-inferior height were consistent with the cadaveric dissection measurements, which provided sufficient access to the anterior and lateral most aspects of the MS. The angle was measured on radiographic imaging, which confirms the ability to visualize and work at the most anterior and lateral aspects of the MS with angled endoscopes. Patient Series In the patient series, five patients presented with an odontogenic cyst in the maxillary sinus; one of which had two retained teeth inside the odontogenic cyst. One patient had an antrochoanal polyp with insertion at the anterior wall of the MS. In all patients, the cyst wall and antrochoanal polyp were completely excised, except when the inferior cyst wall extended to the sinonasal floor to avoid risk of oroantral fistula. The mean Fig. 3. Intraoperative photos obtained with 0 degree endoscope from the left nasal cavity to show the open achieved with TEMMT. (A) Drilling of the medial MS wall after medialization of the IT and elevation of the meatal flap. (B) Exposure of the bony cyst. (C) MS after removal of the cyst. (D) Reposition of the meatal flap and IT for reconstruction of the medial wall of the MS. Observe complete coverage of the medial wall despite some retraction of the flap. IT 5 inferior turbinate; MS 5 maxillary sinus. 1507

Fig. 4. CT coronal view showing the preoperative (A, C) and postoperative (B, D) images of a patient with an odontogenic cyst arising in the left MS treated with the transnasal endoscopic medial MS wall transposition approach. (A, B) Observe the complete resection of the anterior component of the cyst with preservation of the IT. (C, D) Observe the resection of the component of the cyst attached to the tooth root (*) and preservation of the IT and maxillary antrostomy. CT 5 computed tomography; IT 5 inferior turbinate; MS 5 maxillary sinus. duration of follow-up was 13.8 months (range, 11 19 months). Excellent access into the MS, as well as preservation of the nasolacrimal duct, inferior turbinate, and inferior meatus were achieved in all cases. Finally, all mucosal flaps were sufficient to cover the inferior meatal medial maxillary wall antrostomy (Figs. 3 and 4). In Figure 4D, there is residual bony medial MS wall, which was the anterior limit and did not require resection. The inferior half of the lesion in close relation with the floor of the maxillary sinus required TEMMT for access and complete resection. The exposed bone of the nasal floor required 1 month for mucosal regeneration. The only complication identified in the immediate postoperative period was a 1-mm opening in the inferior meatus at the anterior aspect in one patient, which had no morbidity. There were no complications of inferior turbinate instability postoperatively or retraction of the medial wall into the maxillary sinus. DISCUSSION Historically, endoscopic medial maxillectomy (EMM) involved resection of the entire lateral nasal wall, IT, and nasolacrimal duct as described by Sadeghi et al. 3 This provided maximal access to the MS and complete resection, helping to decrease the rate of recurrence for inverting papilloma. Gras-Cabrerizo et al. described preserving the IT by incising the entire length of the IT, leaving it pedicled to the IT artery, then suturing it back 1508 at the end of the case. 4 The limits of the MS access were the floor of the nasal fossa, the posterior wall of the MS, and the anterior wall of the sinus with the nasolacrimal duct anteriorly. Suzuki et al. described a modified EMM technique involving preservation of both the IT and nasolacrimal duct by shifting the mucosa and structures medially to expose the medial maxillary wall and preserving the lateral nasal mucosa. 5 The advantages include wide access with preservation of structures and direct and easier access with straight instruments to the MS through the space anterior to the nasolacrimal duct. 5 However, the approach described did not include a wide mucosal flap from the nasal cavity floor to cover the inferior meatus antrostomy. Our inferior meatal flap allows both wide anterior access to the MS, as well as direct access to the nasal floor, which provides complete coverage of the inferior meatus antrostomy. Because of shrinkage of the mucosa after the flap is harvested, a wide flap is paramount to prevent fistula formation between the maxillary sinus and the inferior meatus. Our first patient had a 1-mm asymptomatic fistula in the anterior aspect of the inferior meatus. For the next five patients, we extended the incision as far anteriorly as possible to the mucocutaneous junction of the nasal sill to avoid excessive shortening of the mucosa once elevated, and none of the patients had a fistula postoperatively. In our transposition technique, the final medial maxillary wall antrostomy accessed through the inferior

meatus is completely covered with the original mucosa allowing the natural drainage system through the maxillary ostium to resume. The TEMMT approach also gives great access to the anterior, lateral, and posterior walls of the MS. Adequate access with straight or curved instruments is the most important aspect to fully excising benign disease and decreasing rates of recurrence. Bony and dentigerous cysts frequently involve the anterior and inferior wall of the MS. This approach provides better intraoperative visualization of the anterior MS. A standard large maxillary antrostomy can also be made for future surveillance purposes and to ensure adequate drainage of the maxillary sinus postoperatively. Therefore, based on our cadaveric dissection and patient series, the TEMMT approach provides ample access, especially with powered instruments, and great visualization of the MS for complete excision of benign MS disease, while minimizing disruption to the natural drainage pathway. The majority of patients in our series were diagnosed with odontogenic cyst, involving the anterior and inferior MS. Therefore, this TEMMT approach provided us the ability to access this area without using a Caldwell-Luc procedure. The most difficult area to visualize and access with instruments endoscopically is the anterior wall; therefore, a wider angle imposes a greater limitation. The radiographic measurement provides an anatomical guide to indicate the range of accessibility and is a foundation for the approach rather than direct clinical applicability. Our study is limited by the small sample size; however, we confirmed accessibility and feasibility with our cadaveric dissection and patient series and evaluated the anatomy with radiographic measurements. Longterm follow-up is needed to determine the return of normal sinonasal function and mucociliary clearance. CONCLUSION TEMMT provides excellent access into the MS, especially the floor and anterior wall, without the morbidities of a Caldwell-Luc or traditional EMM approach. The transposition of the IT and the mucosal flap provides complete restoration of the medial wall and inferior meatus, with preservation of the nasolacrimal duct and inferior turbinate for patients with benign MS disease. Acknowledgments The authors appreciate the support of the Anatomical Gift Program and Clinical Competency Center at Albany Medical College. BIBLIOGRAPHY 1. Vrabec DP. The inverted schneiderian papilloma: a 25-year study. Laryngoscope 1994;104:582 605. 2. Konstantinidis I, Constantinidis J. Medial maxillectomy in recalcitrant sinusitis: when, why and how? Curr Opin Otolaryngol Head Neck Surg 2014;22:68 74. 3. Sadeghi N, Al-Dhahri S, Manoukian JJ. Transnasal endoscopic medial maxillectomy for inverting papilloma. Laryngoscope 2003;113:749 753. 4. Gras-Cabrerizo JR, Massegur-Solench H, Pujol-Olmo A, Montserrat-Gili JR, Adema-Alcover JM, Zarraonandia-Andraca I. Endoscopic medial maxillectomy with preservation of inferior turbinate: how do we do it? Eur Arch Otorhinolaryngol 2011;268:389 392. 5. Suzuki M, Nakamura Y, Nakayama M, et al. Modified transnasal endoscopic medial maxillectomy with medial shift of preserved inferior turbinate and nasolacrimal duct. Laryngoscope 2011;121:2399 2401. 1509