Transorbital Approach for Improved Access in the Management of Paranasal Sinus Mucoceles

Abstract

Introduction  Paranasal sinus mucoceles result from obstruction of mucous glands resulting in a cystic fluid collection that expands and encroaches upon surrounding structures. Transnasal endoscopic marsupialization has largely replaced open resection. However, mucoceles located in the orbital region or the lateral frontal sinus continue to be difficult to approach via the transnasal approach alone and often require additional approaches, such as the frontal trephine. This study sought to investigate the feasibility of the transorbital technique as an adjunct to traditional transnasal approaches in the management of paranasal sinus mucoceles.

Methods  A retrospective case series of paranasal sinus mucoceles approached with a transorbital technique from a tertiary care center.

Results  From 2008 to 2016, 17 patients were treated with a transorbital approach for 20 mucoceles. Of note, 24% of the patients in our series had undergone previous surgical management of the mucocele (nontransorbital approach), representing revision cases. Most mucoceles involved the frontal sinus (82%). The total complication rate was 6%. We observed no new or worsened diplopia, ptosis, or permanent visual loss. Recurrence rate was 6%.

Conclusions  The endoscopic transorbital approach is a feasible complement to transnasal approaches for treatment of mucoceles located in technically challenging locations. We have demonstrated that transorbital approaches can be performed with no resultant orbital damage, visual change, ptosis, or permanent diplopia. While most patients can be treated with a standard transnasal approach, the transorbital approach can be used as part of a multiportal strategy for those with difficult to access mucoceles. Future prospective studies are needed to further characterize patient selection and outcomes.

Introduction

Paranasal sinus mucoceles may result from an obstructed sinus secondary to trauma, previous surgery, inflammation, neoplasm, osteoma, fibrous dysplasia, Paget's disease, or idiopathic. ¹ Associated morbidity often results from expansion into the orbital or intracranial space. Surgical intervention is challenging due to the surrounding critical structures, including the orbit, optic nerve, carotid artery, and skull base. Kennedy et al demonstrated that endoscopic marsupialization of mucoceles is a viable alternative to open procedures for complete resection, ushering in an era of minimally invasive techniques for management of these expansile lesions. ² Previous systematic reivews have demonstrated that even in cases of significant intracranial extension, the morbidity associated with complete resection of the mucosal lining outweighs the benefits, and therefore marsupialization techniques are favored. ³

Endoscopic transnasal surgery has provided effective and safe options for managing most paranasal sinus mucoceles. However, the superior orbit and the lateral frontal sinus are difficult to access (if possible at all) without the addition of an open (or external) approach (i.e., frontal trephine). The frontal trephine is well described and is a proven effective technique. However, with the aid of surgical navigation and fine-cut computed tomography (CT) imaging, transorbital endoscopic approaches to the frontal sinus and anterior cranial fossa have been developed using transconjunctival and transpalpebral pathways to target pathology within or accessible through the orbit. ^{1 4 5} This creates a direct pathway to the frontal sinus and anterior cranial fossa, limits the need for angled endoscopy and instrumentation, and provides a favorable path-to-target trajectory that may be otherwise inaccessible via transnasal or trephine approaches. In particular, the frontal trephine provides a superb anterior–posterior vector of approach but instrument motion in all other directions can be limited, especially in the setting of prior open surgery (e.g., osteoplastic flap or craniotomy) and trauma; whereas the transorbit approach does not suffer from the same constraints. While many surgeons are familiar and facile with trephination techniques, our experience demonstrates that transorbital approaches can provide a more directed approach for selecting mucoceles in far lateral positions or those with anatomy that precludes passage of instruments from medial to lateral (as is used in trephine techinques). Further, the knowledge and skills required for the transorbital approach to the frontal sinus can be easily learned and mastered. This study aims to investigate the safety and feasibility of a transorbital approach, either alone or in conjuction with a transnasal approach, for management of paranasal sinus mucoceles.

Materials and Methods

After approval by the University of Washington institutional review board, we reviewed a prospective database maintained by the senior author (K.S.M.) from 2008 to 2016. We included all subjects who underwent management of a orbital, intracranial, and/or paranasal sinus mucocele with a transorbital approach, regardless of a transnasal endoscopic procedure being performed. No patients were excluded. Demographic data was obtained, as well as information on surgical approach and intraoperative findings. CT scans were also reviewed to determine location and size of the mucoceles. Primary outcomes measured were ability to access and marsupialize the intended target. Seconary outcomes were complications and recurrence.

Surgical Technique and Representative Case

The endoscopic transorbital technique was originally described by Moe et al (2010 and 2011). ^{4 5} Approaches for access include precaruncular (PC), superior eyelid crease (SLC), inferior transconjunctival (ITC), and lateral retrocanthal (LRC) depending on the target of interest. Each variation of the approach results in a distinct vector to the sinuses and skull base. We will discuss the SLC approach which is commonly used for access to sinonasal and orbital mucoceles.

The approach begins with a standard upper eyelid blepharoplasty incision through the skin and orbicularis oculi, maintaining dissection in the preseptal plane. After identifying the septum, dissection is continued up to the superior orbital rim ( Fig. 1 ). The supraorbital and supratrochlear neurovascular bundles are identified and preserved. The periosteum of the orbital rim is then sharply divided allowing for access to the subperiosteal plane. With the aid of a 2.7 or 4 mm 0 degree endoscope, the periosteum is reflected from the orbital bone working posteriorly toward the orbital apex. With image guidance, the pathologic target of interest is identified and the vector of approach for access is confirmed to avoid entering intracranially. If needed for access, an osteotomy in the orbital roof is created using a 3 mm diamond burr and Kerrison's rongeur.

Fig. 1.

Left superior eyelid crease incision.

The mucocele is then decompressed and marsupialized with through-cutting instruments or an ultrasonic bone aspirator, using a combination of 0, 30, and rarely 70 degrees endoscope for visualization ( Fig. 2B and C ). For mucoceles that involve the lateral frontal sinus and orbit, the primary goal is to ensure that there is an unobstructed frontal outflow such that the marsupialized mucocele contents will continue to drain into the nose and not reaccumulate. The frontal intersinus septum can be taken down for help to maintain this if the ipsilateral frontal outflow is permanently obstructed (e.g., penetrating trauma with retained foreign body). In cases of anatomic or inflammatory frontal outflow obstruction, a standard endoscopic transnasal frontal sinusotomy is performed in addition to the endoscopic transorbital approach described above. The techniques of a standard frontal sinusotomy have been previously described. In this series, a Draf's IIb was utilized as necessary. No patients received a Draf's III.

Fig. 2.

( A ) left superior blepharoplasty approach. ( B ) View with 0 degree endoscope through left superior orbital portal with suction passed transnasaly into right frontal outflow tract after marsupialization of mucocele. *superior right (contralateral) orbit, **right (contralateral) lateral frontal sinus. ( C ) illustration demonstrating trajectory of instruments through left superior orbital portal to approach the right lateral frontal sinus.

At completion of the surgical dissection, the orbitotomy is reconstructed with a single sheet of 0.25 mm polydioxanone (PDS) positioned between the bone defect and the periosteum. This is done to prevent prolapse of orbital contents into the frontal sinus. The orbicularis muscle and skin are closed in two layers with absorbable suture.

Results

From 2008 to 2016, 17 patients with 20 mucoceles were managed with transorbital techniques for mucoceles originating from the orbit and paranasal sinuses. All patients had a transorbital approach with 14/17 (82%) undergoing combined transorbital and transnasal endoscopic approaches. Demographic and clinical features of the patients are shown in Table 1 . The majority of patients had involvement of more than one sinus. The distribution of sinuses involved was 82% frontal, 24% ethmoid involvement, 6% maxillary, and 12% intracranial.

Table 1. Clinical features of mucocele patients treated with transorbital approaches.

Age/sex	Clinical history	Mucocele location	Previous surgery to drain mucocele	Approach	Complications	Recurrence	Follow-up
38/M	Right orbital blowout repaired with ORIF from assault with sledgehammer at age 29 y	Right inferior orbit, maxillary, and right ethmoid,	Five previous endoscopic endonasal drainages	Right ITC/transnasa	No	No	7 mo
60/M	Chronic sinusitis and right frontal osteoma removed at age 51 y	Right frontal outflow tract	No	Right SLC/transnasal	No	No	3 y and 6 mo
55/M	Closed head injury at 18 y and previous FESS at age 31 y	Right lateral frontal sinus and superior orbital	No	Right SLC	No	No	2 wk
73/M	No previous trauma or chronic sinusitis	Right frontal sinus and superior orbit	No	Right SLC/transnasal	No	No	1 mo
57/F	Chronic sinusitis	Left frontal sinus and superior orbit	No	Left SLC/transnasal	No	No	1 y
60/M	Chronic sinusitis	Left frontal sinus and superior orbit	No	Left SLC/transnasal	DVT postop d 4	No	3 y and 5 mo
58/F	Bilateral orbital blow-out fractures from MVC age 56 y repaired with ORIF	Left orbit	No	Left PC, removal of hardware	No	No	9 mo
35/M	GSW to FOM that transversed nose and left orbit, repaired with cranialization of frontal sinus age 17 y	Left superior and medial orbit extending to anterior ethmoid and left frontal sinus	No	Left SLC/transnasal	No	No	6 mo
43/M	Chronic sinusitis	Left frontal sinus outflow tract	No	Left PC/transnasal	No	No	2 y and 10 mo
38/M	Left anterior table fracture after trauma to skull with chain and ORIF age 16 y	Three separate mucoceles, bilateral and central frontal	No	Bilateral SLC transorbital	No	No	4 mo
27/M	Nail gun to orbit as child with medial wall fracture	Left frontal and superior orbit with extension into anterior cranial fossa and anterior ethmoids	Frontal craniotomy and resection of mucocele 4 mo prior	Right PC/transnasal	No	No	2 y and 6 mo
29/M	Frontal sinus fracture age 23 y with ORIF	Right superior orbit	Previous ethmoidectomy and frontal sinus drill out	Right SLC/transnasal	No	No	2 y and 6 mo
34/M	Pipe impaled frontal sinus, nose and frontal lobe age 18 y, no repair at that time, delayed repair of CSF leak	Left orbital roof extending intracranially	No	Left SLC/transnasal	CSF leak requiring repair 2 wk postop; bilateral PE in the immediate postop period	Yes; currently considering options for repair (last seen: December 2015)	4 y
52/M	Anterior table fracture from MVC repaired with ORIF age 37 y	Left lateral frontal sinus and superior orbit	No	Left SLC/transnasal	No	No	4 mo
48/M	Anterior table and right inferior orbital rim from MVC both repaired with ORIF, age 28 y	Right medial, anterior and posterior orbit with extension into the ethmoid roof extending near frontal outflow tract	Endoscopic drainage 8 mo prior	Right SLC/transnasal	No	No	6 mo
49/M	Anterior and posterior table fracture from GSW to the glabela s/p ORIF age 33 y	Right fronto-orbital and left fronto-orbital	No	Left SLC/transnasal	CSF leak repaired postop d 8	No	4 mo
23/F	No previous trauma, osteoblastoma	Right fronto-orbital	No	Bilateral SLC/transnasal	No	No	4 mo

Abbreviations: CSF, cerebrospinal fluid; DVT, deep vein thrombosis; F, female; FESS, fuctional endoscopic sinus surgery; FOM, floor of mouth; GSW, gun shot wound; ITC, transconjunctival; M, male; MVC, motor vehicle collision; ORIF, open reduction internal fixation; PC, precaruncular; PE, pulmonary embolism; postop, postoperative; SLC, superior eyelid crease.

In this case series, the most common etiology was isolated craniofacial trauma (11/17, 65%), of which 9 (53%) had previous operative fixation of craniofacial trauma. The most common injuries leading to mucocele formation were frontal sinus fractures (six patients) and orbital fractures (five patients). Importantly, four of seventeen patients (24%) had failed a prior surgical procedure (nontransorbit). Of these, one patient had a frontal craniotomy and the remaining three underwent transnasal approaches. Lastly, one patient had four previous transnasal procedures, prior to a transorbital approach.

Our average follow-up was 18 months for all patients (range: 2 weeks–4 years). Shorter duration of follow-up occurred for patients who lived a long distance from our institution and consequently received follow-up care by local otolaryngologists.

The complication rate was low with one complication in a single patient (6% of the series). This was an iatrogenic cerebrospinal fluid (CSF) leak caused while attempting to establish mucocele drainage in a supraorbital ethmoid cell. Conservative management was employed but the patient did require takeback for repair 1 week later. There was also one recurrence in a patient who is currently declining further treatment and followed closely by our clinic. There were no new or worsened cases of ptosis, permanent visual loss, or new postoperative diplopia.

Discussion

This case series demonstrates the feasibility and applicability of transorbital endoscopic management in sinonasal, orbital, and intracranial mucoceles. Transorbital endoscopic surgery is a novel, viable technique to provide access to paranasal sinus mucoceles in technically challenging locations when the transnasal endoscopic approach alone is insufficient or inadequate. The intent of the transorbital approach is not to replace transnasal or trephine techniques but rather serve as an additional tool allowing the surgeon greater access to pathology in challenging regions, namely, the lateral frontal sinus and orbit.

Despite the high-risk anatomic location of the expansile lesions in our case series, we have demonstrated feasibility and an excellent safety profile for a transorbital approach. All mucoceles were successfully reached and marsupialized as intended. There were no incidences of new visual deficits, worsened diplopia, or worsened ptosis. Additionally, we did not experience unfavorable wound healing, eyelid distortion, or poor cosmetic outcomes associated with the periocular incisions. Postoperative diplopia may occur for several weeks after surgery depending on the location of pathology, degree of retraction during surgery, and previous globe displacement by the mucocele; however, permanent diplopia due to surgical intervention was not seen in this series. Temporary forehead paresthesia, typically lasting 3 to 6 months, is an expected outcome during superior transorbital approaches due to dissection and retraction of the supraorbital neurovascular bundle. There were no incidents of permanent hypesthesia or anesthesia.

Our one complication was a CSF leak in a patient who suffered a penetrating injury by a pipe to his frontal sinus and skull base 16 years prior. The patient was initially treated at an outside hospital with a frontal craniotomy and frontal sinus cranialization. The patient subsequently developed a mucocele based on the orbital roof with resultant intracranial extension. The patient was treated with a combined transorbital and transnasal approach. Due to the significant dissection required to eradicate the mucocele, a dural tear occurred in the tight confines of the supraorbital ethmoid cell ( Fig. 3A ). This leak was initially treated conservatively but ultimately required transorbital endoscopic surgical intervention for repair 2 weeks after the initial surgery. However, the repair caused partial obstruction of the mucocele's outflow tract and the patient experienced a delayed recurrence. The patient was offered a revision but declined. He is currently 5 years out from his surgery and has not had sequela from the recurrent mucocele. This patient underwent initial surgery early in the series (2011) and served as a paradigm change to our surgical strategy. Currently, our approach for this is to drain the mucocele into the frontal sinus where there is a larger cavity rather than into the more confined ethmoid region demonstrated in Figs. 3B , 4 , and 5 .

Fig. 3.

Patient with iatrogenic CSF leak. ( A ) Mucocele with orbital and intracranial extension. ( B ) Purple vector demonstrates drainage to ethmoids, the original drainage pathway which resulted in CSF leak. Note the minimal clearance from the dura. Yellow vector demonstrates safer drainage into the frontal sinus, the preferred pathway. CSF, cerebrospinal fluid.

Fig. 4.

( A ) Coronal, ( B ) sagittal, and (C) axial CTs demonstrating extent of the pathology after surgical resection. ( D ) Lateral view from left transorbital approach into right mucopyocele demonstrating impaction. ( E ) View from right superior transorbital approach looking into right frontal mucocele defect as in figure A. Note : suction on inferior aspect of exposed frontal lobe dura. The leak was at the bone margin, located deep to the mucosa seen at the top of the image. CT, computed tomography.

Fig. 5.

Coronal fat suppression sequence MRI ( A ) and coronal CT ( B ) demonstrating location of intracranial mucocele and cranialized frontal sinus. CT, computed tomography; MRI, magnetic resonance imaging.

The previously mentioned case accounts for our only complication and recurrence to date. Recurrence rates in the literature range greatly based on length of follow-up. Devars du Mayne et al reviewed the literature and reports a 0.9 to 24% recurrence rate in 3.5 to 7 years after treatment with a variety of endoscopic and open approaches. ⁶ In a meta-analysis, frontal mucocele recurrence rates were between 3 and 10%, whereas complication rates were between 2 and 5%. ⁷ Our recurrence and complication rate of 6% is consistent with that reported.

We acknowledge several limitations in our study including small sample size, inherient issues with retrospective reviews and short mean follow-up time, limiting our ability to pick up late failures. We acknowledge that limited conclusions can be drawn without a comparision or control group and that this study is descriptive in nature. However, these data are important in building a proof of concept and foundation for future studies. Importantly, future study is needed to compare outcomes with other techniques that are more widely accepted (e.g., frontal trephination).

Conclusion

Endoscopic transorbital approaches are a useful complement to endoscopic transnasal approaches for the treatment of paranasal sinus mucoceles when they are located in anatomically or technically challenging locations. Both approaches offer complimentary but different technical advantages. In this initial series, we have shown that transorbital approaches are feasible and can be safely performed without resultant orbital damage, visual change, ptosis, or permanent diplopia. In addition, we have shown that in 94% of our patients with highly complex pathology, this approach can provide successful, definitive treatment of mucocele pathology without evidence of recurrence. Standard transnasal endoscopic approaches remain the method of choice for the majority of patients with paranasal sinus mucoceles. However, in situations where mucocele location or access is limited with transnasal techniques alone, a transorbital approach can be useful complimentary tool.

Funding Statement

Funding Source National Institutes of Health (NIH) T32 Institutional Ruth L. Kirschstein Service Award T32DC000018 (PI: Edward Weaver).