Published: mors- A 28 Year Experience Copyright€¦ · approaches to the anterior skull base have evolved over the past 50 years. A variety of open, endoscopic and endoscopic-assisted

Central Annals of Otolaryngology and Rhinology

Cite this article: Del Signore Pharm AG, Reino A, Weinberg A, Lawson W (2014) The Superior Rhinotomy Approach: Resection of Bilateral Sinonasal and Skull Base Tumors- A 28 Year Experience. Ann Otolaryngol Rhinol 1(2): 1007.

*Corresponding authorWilliam Lawson, MD; Department of Otolaryngology— Head and Neck Surgery Icahn School of Medicine at Mount Sinai; One Gustave L. Levy Place; Box 1189; New York, NY 10029; Tel:1-212-241-1599;Fax-1-212-831-3700; Email:

Submitted: 17 September 2014

Accepted: 23 September 2014

Published: 17 October 2014

Copyright© 2014 Lawson et al.

OPEN ACCESS

Keywords•Superior rhinotomy•Ethmoid tumors•Craniotomy•Transfacial approach•esthesioneuroblastoma

Research Article

The Superior Rhinotomy Ap-proach: Resection of Bilateral Sinonasal and Skull Base Tu-mors- A 28 Year ExperienceAnthony G. Del Signore Pharm1; Anthony Reino2, Alan Weinberg3 and William Lawson1*1Department of Otolaryngology, Icahn School of Medicine at Mount Sinai, USA2Department of Otolaryngology, JJ Peters Veterans Affairs Medical Center, USA3Department of Health Evidence and Policy, Icahn School of Medicine at Mount Sinai, USA

Abstract

Objectives: Introduced almost 30 years ago there has been no published follow up on this novel external approach to a select group of bilateral ethmoid and anterior skull base lesions. We review the complications and long-term results of the superior rhinotomy approach.

Study Design: Retrospective review.

Methods: From 1985 to 2013, fifty-nine patients presenting to a tertiary care medical center with bilateral ethmoid tumors with and without intracranial extension were resected utilizing the superior rhinotomy approach. Tumors were classified by pathology and stage at presentation. Long term outcomes and complications were reviewed.

Results: Fifty-nine patients with bilateral ethmoid tumors were treated by the superior rhinotomy technique, with or without a bifrontal craniotomy. The mean age of this cohort was 55 years. The mean duration of the follow up was 91 months. Complication rates were noted primarily in patients undergoing craniotomy and adjuvant radiotherapy; and consisted of central nervous system, functional, cosmetic, wound and systemic complications.

Conclusions: In this endoscopic age it is important to retain approaches that may assist in the treatment of large ethmoid lesions. As described, the superior rhinotomy is a safe, versatile and highly effective approach for the en-bloc resection of advanced malignancy of the ethmoid sinuses. Based on our experience the authors feel that this approach should be part of the otolaryngologist’s armamentarium for the treatment of advanced disease of the bilateral ethmoid sinuses and the anterior skull base.

INTRODUCTIONMalignant tumors of the paranasal sinuses and nasal cavity

account for 3-5% of head and neck malignancies [1].Previous reports have noted approximately 10% of tumors arising from the sinonasal tract involving either the ethmoid or frontal sinuses[2].The indolent nature, histological diversity and ambiguous symptoms associated with ethmoid sinus neoplasms have resulted in presentation at an advanced stage associated with poor prognosis. Furthermore, their unique lymphatic drainage, location adjacent to the orbit and the anterior skull base allows for extrasinal and intracranial extension.

Based on the seminal work of Dandy [3] and Ketcham [4], approaches to the anterior skull base have evolved over the past 50 years. A variety of open, endoscopic and endoscopic-assisted open approaches have been described in the literature for the treatment of advanced anterior skull base lesions. The goal of all approaches is to provide “oncologic” resection with minimal morbidity to surrounding structures and little to no significant cosmetic deformity. Initially introduced by Lawson and Biller [5], the superior rhinotomy approach encompasses these tenants, allowing excellent visualization of bilateral ethmoid sinuses, orbits and anterior skull base while providing a means for resection of advanced intracranial disease.

Central

Lawson et al. (2014)Email:

Ann Otolaryngol Rhinol 1(2): 1007 (2014) 2/6

With a plethora of endoscopic approaches and the increased comfort among practitioners, the transfacial approach is used less commonly in addressing anterior skull base lesions. Current evidence demonstrates equivalent short-term outcomes for both endoscopic and open techniques, with a preponderance of higher stage lesions being addressed with open techniques [6]. Although the pendulum has swung in many tertiary centers, it is important to discuss other available approaches for skull base surgeons in the treatment of advanced anterior skull base lesions. We present our experience describing the surgical advantages, complications and outcomes of the superior rhinotomy in the resection of extensive benign and malignant tumors of the paranasal sinuses.

MATERIALS AND METHODSThis retrospective study was based on a review of the

hospital charts of all consecutively treated patients undergoing transfacial resection via the superior rhinotomy approach by the senior authors (W.L. and A.R.) at the Icahn School of Medicine at Mount Sinai. The study protocol was approved by the Mount Sinai Institutional Review Board. We identified fifty-nine patients within the senior author’s personal database with both benign and malignant ethmoid tumors treated from 1985 to 2013.

All available names and surgical dates from the senior author’s database were obtained. Only patients with available medical charts were included in the analysis. Records were reviewed regarding patient sex, age at diagnosis, site of lesion, pathology, staging, primary versus recurrent disease at first presentation to our institution, radiographic findings, extent of resection, complications, duration of follow up, recurrence, post operative treatment. Complications were divided into five categories; central nervous system, functional, wound, cosmetic and systemic. When available, imaging was reviewed and staged according to the 7th edition of the American Joint Committee on Cancer staging manual, [7] otherwise the available report or assessment was abstracted to provide extent of disease.

Statistical methods

Poisson regression (i.e. Generalized Linear Modeling) was used to compare cumulative complication rates among treatment groups, and the various stages, taking account of length of follow-up per patient. For all statistical analysis, data was analyzed using the SAS System software (SAS Institute, Inc., Cary, N.C).

Surgical technique

Upon induction of general or tracheal anesthesia, bilateral skin incisions are marked over the front maxillary processes, beginning at the medial aspect of the eyebrows and extending down the inferior border of the nasal bones. A transverse limb made across the glabella joins the two vertical incisions. (Figure 1) Subcutaneous lidocaine and epinephrine (1:100,000 concentration) is injected. Skin and subcutaneous tissue are incised down to the periosteum. The periosteum of the orbit is incised and elevated toward the lacrimal fossa. The medial canthal ligament is detached and marked for reattachment. The lacrimal sac is dislocated from the fossa and transected as distally as possible and averted with tacking sutures of 4-0 chromic catgut. The periorbita is elevated posterior until the anterior ethmoid artery is identified, electro coagulated and divided. The

periosteal elevation proceeds inferiorly along the medial orbital wall to the orbital floor and over the orbital roof.

The periosteum is incised across the frontal processes of the maxilla and the nasofrontal processes, and elevated 1 centimeter in both directions. Lateral osteotomies are made low along the frontal process of the maxilla. The bony nasal pyramid is detached by a transverse osteotomy across the glabella allowing the nose to be reflected downward and hinged inferiorly by its soft tissue attachments. Care is taken to leave as much dorsal cartilaginous septum as oncologically feasible to serve as a L-shaped strut to prevent nasal collapse. The superior rhinotomy can be combined with unilateral or bilateral medial maxillectomies, depending on the extent of disease.

Nasoethmoidal tumors contiguous with the floor of the anterior cranial fossa or intracranial extension, the superior rhinotomy can be combined with a bifrontal craniotomy to expose the entire anterior skull base. An inferiorly based peri cranial flap can be used to resurface the floor of the anterior fossa. After the cranial bone flap is removed, the frontal lobes are retracted and the posterior wall of the frontal sinus is removed with a ranger so that the anterior bone cut can be made immediately behind the anterior table of the frontal sinus. This permits complete resection of the floor of the anterior fossa in an en bloc fashion.

Preservation of the nasal process of the frontal bone provides a point of fixation for reattachment of the nasal pyramid, preventing nasal collapse with its attendant functional and cosmetic deformities. The lateral and posterior intracranial bone cuts are determined by the extent of the tumor. The superior bone cuts of the bilateral medial maxillectomies are joined to the intracranial osteotomies under direct visualization. The remainder of the medial maxillectomy is performed in standard fashion and the en bloc specimen is delivered downward and outward through the nasal cavity. (Figure 2a) Intraoperative frozen section is performed to control margins.

Once negative margins are obtained, dural defects are repaired. Using the resultant defect the medial canthal ligaments are sutured to each other with a 3-0 polypropylene suture. (Figure 2b) Antibiotic impregnated packing is placed intra-nasally along the skull base, orbital wall, and nasal cavity. The nasal pyramid is reattached to the frontal bone with an X-shaped miniplate. The subcutaneous tissues and skin are carefully re-approximated in layers to complete the closure.

Figure 1 Schematic drawing of the incisions for the superior rhinotomy approach.

Central

Lawson et al. (2014)Email:

Ann Otolaryngol Rhinol 1(2): 1007 (2014) 3/6

RESULTSFifty-nine patients were identified in the senior author’s

database that underwent anterior craniofacial resection via the superior rhinotomy incision between 1985 and 2013. The authors’ database included a wide variety of pathologies treated using this approach (Table 1).

Of these, 24 patients were found to have complete charts and were used for the analysis. Demographic data is presented in (Table 2). Three-fourths of our patients (n=18) required a combination of a transfacial and a craniotomy approach to clear the disease. Of those, 44% required a pericranial flap for reconstruction, while solely autologous non vascularized graft and temporalis fascia graft were used much less frequently, 11% and 4% respectively. Thirty-nine percent had a combination of reconstructive materials for the resultant dural defects, including temporalis fascia, pericranium, alloderm, and /or fat.

The central nervous system (CNS) complications occurred in six patients, functional issues in five patients, cosmetic issues in four patients, wound infections in four patients, and systemic issues in one patient (Table 3).

Of the CNS complications encountered, three patients necessitated a return to the operating room; two for the immediate repair of a CSF leak noted on postoperative imaging, one for repair of a CSF leak and one patient for evacuation of an intracranial hematoma. The remaining three patients had complications that were managed expectantly, spontaneous resolution of pneumocephalus and a cranial infarct that had full resolution of all symptoms.

Of the functional complications noted, two patients developed epiphora upon completion of radiation therapy and required endoscopic dacrocystorhinostomy for full resolution of symptoms. Four patients developed diplopia and treated conservatively, three with rehabilitation and one with a prism lens.

Three patients were noted to develop resorption of the post craniotomy frontal bone flap after radiation therapy. Two patients developed the sequel greater than 5 years post operatively, while one developed resorption in the second postoperative year. Two patients developed nasal cosmetic issues, consisting of vestibular stenosis and nasal collapse, both occurring after radiation therapy.

Three patients developed wound complications necessitating operative intervention. Two patients developed a mucosal two years post operative, initially suspicious for a recurrence; it was drained with no evidence of tumor. One patient developed a frontal bone infection, which resolved with craniotomy and long-term intravenous antibiotics.

When comparing the incidence of complications to both the extent of the treatment and stage, a significant difference was noted amongst patients with both craniotomy and radiation therapy and those with higher staging (Table 4). When compared to stage 3 disease, the incidence of complications was 3.78 more likely in stage 4a disease and 7.1 times more likely in stage 4b disease.

Within the 91-month follow up period, there were three local recurrences, five regional recurrences and one distant metastasis(Table 5). Due to small sample size and diverse pathologies encountered, an accurate survival rate could not be calculated.

A)

B)

Figure 2 Superior rhinotomy A) Specimen being delivered en bloc via superior rhinotomy incision site. B) Resultant defect via the superior rhinotomy approach.

Tumor n

Benign (n=14)

Inverted Papilloma 8

Hamartoma 3

Pseudotumor 2

Ameloblastoma 1

Malignant (n=45)

Esthesioneuroblastoma 16

Squamous cell carcinoma 7

Undifferentiated Carcinoma 7

Neuroendocrine Carcinoma 4

Spindle Cell Carcinoma 2

Hemangioma 2

Adenocarcinoma 2

Chondrosarcoma 1

Transitional cell Carcinoma 1

Melanoma 1

Rhabdomyosarcoma 1

Fibrosarcoma 1

Table 1: Distribution of benign and malignant sinonasal pathology treated via the superior rhinotomy approach.

Central

Lawson et al. (2014)Email:

Ann Otolaryngol Rhinol 1(2): 1007 (2014) 4/6

DISCUSSIONThe versatility and adaptability of the superior rhinotomy

approach provides the ability for the resection of advanced lesions within the nasal cavity, paranasal sinuses with orbital and intracranial involvement. The incisions described provide unobstructed entry allowing full resection of the cribriform plate, fovea ethmoidalis, bilateral orbital walls, floor of the frontal sinus and face of the sphenoid. Additionally, when combined with a medial maxillectomy, en bloc resection of extensive bilateral tumors can include the party-wall between the nasal cavity, orbit and antrum. More advanced lesions with extension through the ethmoid roof into the anterior cranial fossa are addressed by a combined superior / inferior approach utilizing a frontal craniotomy [5]. Multiple reconstructive techniques to repair dural and anterior skull base defects with the use of per cranial flaps additionally decreases operative morbidity [8, 9].

In advanced disease, the technical limitations encountered with transnasal endoscopic approaches often become evident.

Demographic Data (n=24) (%)

Mean age, years 55.25 < 65 y/o 20 83% > 65 y/o 4 17%Male sex (%) 16 67%Histology (%) Esthesioneuroblastoma 11 45% SNUC 3 12% SNEC 2 8% SCC 2 8% IP 2 8% Other 4 17%Stage III 10 42% IV a 4 16% IV B 10 42%Surgical approach

Transfacial alone 6 25%Combined approach 18 75%

Skull base reconstruction Pericranial flap 8 44% Autologous nonvascularized 2 11% Temporalis fascia 1 4% Combination 7 39%Adjuvant Therapy Radiation 14 60% Chemoradiation 9 40%Mean Follow up, months 91.4 Site of Recurrence Local 3 13% Regional 5 21% Distant 1 4%

Table 2: Demographic data.

Complication EventsCentral Nervous System Pneumocephalus 3 CSF leak 2 Intracranial bleed 1 Cranial infarct 1Functional Diplopia 4 Epiphora 2Cosmetic Frontal bone resorption 3 Vestibular stenosis 1 Nasal collapse 1Wound Mucocele 2 Bone flap infection 1 Cellulitis 1Systemic Pulmonary embolism 1

Table 3: Complications encountered in studied patient population.

Extent of treatment

No. of Patients

Total Complications

Follow up (patient years)

V TF 4 0 19.4

TF + C 6 6 47

TF + XRT 2 0 18.4

TF + C + XRT 12 18 70.7

Stage

III 10 3 70.9

IV a 4 5 31.2

IV b 10 12 53.4TF= Transfacial; C= Craniotomy; XRT= radiation; ^= vs. TF; *= vs. stage 3

Table 4: Incidence of complications based on extent of treatment.

Recurrence Initial pathology

Initial stage

Postop week

Secondary treatment

Local

Frontal lobe ENB IV b 70 CRT

Clival ENB IV a 1240 E / XRT

Nasal floor SCC III 189 E / XRT

Regional

Unilateral level 1 LN SNUC IV b 72 SND

Retropharyngeal LN ENB III 88 XRT

Bilateral level 2 LN SCC IV b 96 B/L SND

Axillary LN SCC IV b 416 E / XRT

Unilateral level 2 LN ENB IV b 102 SND

Distant

Spinal metastasis SNUC IV b 65 ITC / XRTLN: lymph node; SND: selective neck dissection; E: excision; XRT:

radiationCRT: Chemo radiotherapy; ITC: Intrathecal chemo; SCC: Squamous cell ca

ENB: esthesioneuroblastoma; SNUC: Sinonasal undifferentiated ca

Table 5: Recurrences noted as compared to initial pathology and stage treated.

Central

Lawson et al. (2014)Email:

Ann Otolaryngol Rhinol 1(2): 1007 (2014) 5/6

These include an inability to suture, difficulty of assessing tumor extent around corners, and difficulty in controlling large vessels in the case of bleeding[10]. Absolute and relative contraindications to endoscopic resection have been proposed, including; invasion of facial soft tissue by malignancy, highly vascular tumors, need for orbital exoneration, lateral tumor extension with invasion of the pterygomaxillary space / infratemporal fossa, and extensive bilateral disease[11]. Given the unobstructed view of the open exposure, many of these limitations can be overcome. Furthermore, the approach allows a safe oncologically sound resection; as close or positive margins can significantly affect survival[12].

Craniofacial surgery has been shown to be a safe technique for patients with large bulky and intracranial tumors. As illustrated, we had no perioperative mortality. Mertz et al noted a perioperative mortality of 0.9% when utilizing an open approach in a series of 226 patients [13]. Other authors have noted a similar perioperative mortality rate associated with anterior cranial facial surgery of 0-4% [12, 14-16].

The incidence of complications; including wound infections, meningitis, CSF leakage, intracranial abscess, pneumocephalus, and orbital complications have been reported up to 33%[10, 12, 15-17]. Complication rates are intimately related to patient co morbidity status, tumor burden, intracranial extension and radiation delivery[12]. Our complication rates were noted to be similar to the literature, with a preponderance to higher stage and aggressiveness of treatment.

Our series had two CSF leaks; both were repaired with temporalis fascia with subsequent resolution of the leak. One patient began leaking after radiation therapy, and was found to have a dehiscence in the field of radiation. Dural closure was achieved with a temporalis fascia graft. Two cases of intraparenchymal cranial hemorrhage were noted on postoperative imaging. Both patients were treated conservatively and subsequent CT scans revealed a stable collection and no further intervention was needed. Neurologic complications can be minimized with fastidious closure of dural defects, minimization of cranial retraction during resection and recruiting robust vascular tissue in cases of previous radiation.

Functional complications are typically due to technical errors, with the most disastrous orbital complication being loss of vision. Since the superior rhinotomy provides full exposure of both ethmoid arteries, this grave complication can potentially be bilateral. Meticulous care must be taken while gaining hemostasis of the anterior and posterior ethmoid artery, as excessive electro coagulation can place the optic nerve at risk. Careful reapproximation of the periorbita is also imperative to prevent disruption of the supporting structures. A non-absorbable suture is used to reapproximate the medial canthal ligaments to each other. Only one patient experienced persistent diplopia, early in the series, which was lessened with retraining and therapy. Another patient experienced transient diplopia that subsequently resolved with therapy. The authors have found it imperative to record pre-resection intercanthal distances to ensure optimal vision outcome.

Another minor complication, postoperative epiphora, may occur secondary to stenosis of the nasolacrimal apparatus. The

incidence was increased in patients receiving postoperative radiotherapy. Thus, the senior authors prefer to marsupialize the nasolacrimal duct after severing it within the nasolacrimal fossa, however, the possibility also exists to stent the duct with polyethylene tubes.

Cosmetic outcomes with other reported open approaches have been found to be less than ideal. The total rhinotomy allows the entire external nose to be swung to the contra lateral side of the face, by the separation of bony attachments of the nasal pyramid, transection of the columella and nasal septum. Unfortunately, severing these major support structures, the entire external nose is nearly completely destabilized increasing possible cosmetic and functional complications. As Bernard et al demonstrated, even the lateral rhinotomy has been shown to have a 10% late complication rate, including nasal collapse, saddle deformity, columellar collapse, and alar retraction[14]. Some contributing factors were found to be in patients with extensive resections including medial maxillectomy, prior operations or perioperative radiation. Our series further supports these contributing factors as 40% of the cosmetic complications noted were secondary to adjunctive radiation exposure.

The superior rhinotomy allows maintenance of a robust L-strut and intact inferior caudal septum, minimizing the postoperative nasal functional deficits and cosmetic deformities. Despite the number of incisions associated with the described procedure, aesthetic complications were minimal and postoperative cosmesis was excellent. Careful closure and utilization of plastic surgery layered closure results in minimal facial scarring[18]. Authors further state that not one patient in the series were deterred or psychologically prevented from pursuing an active life. That being said, early in the post operative period patients may develop minor transient nasofacial edema, which regresses with conservative therapy. In fact due to superior cosmesis and versatility of the approach, the senior authors began implementing the treatment of some advanced unilateral ethmoid tumors.

We are mindful of several limitations related to the retrospective design of our study. First, due to the extent of time that the superior rhinotomy has been performed at our institution, many of the charts were not available for review and thus limit a true representation of our experience using this technique. Although patient demographic data and pathology were recorded, a full review of all patient chart treated was not possible. Secondly, given the nature of a tertiary care hospital, many of the patients receive the operative treatment and then pursued adjuvant treatment and follow up in their hometown. Thus, many of the charts were found to be incomplete with minimal, if any follow up data on adjuvant treatment modality and mortality data.

CONCLUSIONIn conclusion, as endoscopic sinus surgery approaches to

skull base lesions increase and indications are being expanded, adjuvant external approaches to the skull base, such as the superior rhinotomy are important to study. The approach becomes especially important when disease extent is not adequate for solely endoscopic resection, providing a wide field

Central

Lawson et al. (2014)Email:

Ann Otolaryngol Rhinol 1(2): 1007 (2014) 6/6

Del Signore Pharm AG, Reino A, Weinberg A, Lawson W (2014) The Superior Rhinotomy Approach: Resection of Bilateral Sinonasal and Skull Base Tumors- A 28 Year Experience. Ann Otolaryngol Rhinol 1(2): 1007

Cite this article

exposure for en bloc resection of advanced sinonasal tumors. When combined with a craniotomy, a composite resection of both the intracranial component and sinonasal disease can be accomplished. Cosmetic outcome is not compromised, as may occur with other open procedures. The authors strongly feel the approach should be part of the otolaryngologist’s armamentarium for the treatment of advanced disease of the ethmoid sinuses and anterior skull base.

REFERENCES1. Haerle SK, Gullane PJ, Witterick IJ, Zweifel C, Gentili F. Sinonasal

carcinomas: epidemiology, pathology, and management.. Neurosurg Clin N Am. 2013; 24: 39-49.

2. Osguthorpe JD, Patel S. Craniofacial approaches to tumors of the anterior skull base. Otolaryngol Clin North Am. 2001; 34: 1123-1142.

3. Dandy W. Orbital Tumors: Results Following the Transcranial Operative Attack. Oskar Priest 1941:168-188.

4. KETCHAM AS, WILKINS RH, VANBUREN JM, SMITH RR. A COMBINED INTRACRANIAL FACIAL APPROACH TO THE PARANASAL SINUSES. Am J Surg. 1963; 106: 698-703.

5. Biller HF, Slotnick DB, Lawson W, Green RP. Superior rhinotomy for en bloc resection of bilateral ethmoid tumors.. Arch Otolaryngol Head Neck Surg. 1989; 115: 1463-1466.

6. Soler ZM, Smith TL. Endoscopic versus open craniofacial resection of esthesioneuroblastoma: what is the evidence?. Laryngoscope. 2012; 122: 244-245.

7. Cancer AJCo. AJCC Cancer Staging Handbook: Springer Verlag, 2010.

8. Price JC, Loury M, Carson B, Johns ME. The pericranial flap for reconstruction of anterior skull base defects.. Laryngoscope. 1988; 98: 1159-1164.

9. Johns ME, Winn HR, McLean WC, Cantrell RW. Pericranial flap for the closure of defects of craniofacial resection.. Laryngoscope. 1981; 91: 952-959.

10. Su SY, Kupferman ME, DeMonte F, Levine NB, Raza SM, Hanna EY. Endoscopic resection of sinonasal cancers.. Curr Oncol Rep. 2014; 16: 369.

11. Eloy JA, Vivero RJ, Hoang K, Civantos FJ, Weed DT, Morcos JJ, et al. Comparison of transnasal endoscopic and open craniofacial resection for malignant tumors of the anterior skull base. Laryngoscope. 2009; 119: 834-840.

12. Patel SG, Singh B, Polluri A, Bridger PG, Cantu G, Cheesman AD, et al. Craniofacial surgery for malignant skull base tumors: report of an international collaborative study. Cancer. 2003; 98: 1179-1187.

13. Mertz JS, Pearson BW, Kern EB. Lateral rhinotomy. Indications, technique, and review of 226 patients.. Arch Otolaryngol. 1983; 109: 235-239.

14. Bernard PJ, Biller HF, Lawson W, LeBenger J. Complications following rhinotomy. Review of 148 patients.. Ann Otol Rhinol Laryngol. 1989; 98: 684-692.

15. Ganly I, Patel SG, Singh B, Kraus DH, Bridger PG, Cantu G, et al. Complications of craniofacial resection for malignant tumors of the skull base: report of an International Collaborative Study. Head Neck. 2005; 27: 445-451.

16. Ganly I, Patel SG, Singh B, Kraus DH, Bridger PG, Cantu G, et al. Craniofacial resection for malignant paranasal sinus tumors: Report of an International Collaborative Study. Head Neck. 2005; 27: 575-584.

17. Solero CL, DiMeco F, Sampath Pet al. Combined anterior craniofacial resection for tumors involving the cribriform plate: early postoperative complications and technical considerations. Neurosurgery. 2000; 47:1296-1305.

18. Loy AH, Reibel JF, Read PW, Thomas CY, Newman SA, Jane JA, et al. Esthesioneuroblastoma: continued follow-up of a single institution’s experience. Arch Otolaryngol Head Neck Surg. 2006; 132: 134-138.