Surgical Instructions in Revision Endoscopic Sinus Surgery: Pearls and Pitfalls

Abstract

Functional endoscopic sinus surgery (FESS) has become one of the most common surgical techniques performed by otolaryngologists with significant data demonstrating its efficacy in managing patients with chronic rhinosinusitis (CRS). However, despite this initial success, patients may continue to present with recurrent symptoms and approximately 10–15% of them will require revision surgery. Failure of FESS may have many different causes which include inappropriate patient selection and preparation, comorbidities like cystic fibrosis and Samter’s triad, insufficient surgical skills or anatomical variations that have not been addressed adequately. Two inverse European techniques were introduced in the 1980s. The one promoted by Messer–klinger, who practiced the anterior-to-posterior approach, another one, developed by Wigand who performed posterior-to-anterior dissection, opens the sphenoid ostium or removes the anterior wall of the sphenoid sinus and ends with a total ethmoidectomy. Hereby in RESS we start dissection in posterior-to-anterior fashion by following a structured approach in the identification of the fixed landmarks to allow quick and easy orientation to the skull base and medial orbital wall to avoid the complications.

Electronic supplementary material

The online version of this article (10.1007/s12070-020-01861-6) contains supplementary material, which is available to authorized users.

Introduction

Functional endoscopic sinus surgery (FESS) has become one of the most common surgical techniques performed by otolaryngologists over the last three decades with a significant data demonstrating its efficacy in combination with medical treatments in managing patients with chronic rhinosinusitis (CRS) [1–5]. Failure of FESS may have many different causes which include inappropriate patient selection, preparation, comorbidities like (cystic fibrosis and Samter’s triad), insufficient surgical skills, anatomical variations and inadequate postoperative cavity debridement [5, 6]. The contribution of the underlying pathology to a primary surgical failure is a critical factor to consider, nasal polyposis is a common cause for revision surgery and is most likely a manifestation of the combination of environmental exposure and excessive host response [7, 8]. Poor surgical technique includes the following impacts; (1.) Mucosal stripping results in bony exposure with subsequent neo-osteogenesis, excessive scarring and synechiae formation. (2.) Circumferential mucosal resection with scarring of the ostia during the healing process. (3.) Surgically performed ostia that do not encompass the natural ostia will generate a recirculation phenomenon, make the sinus prone to contamination and persistent infection. (4.) Incomplete removal of the ethmoidal cells resulting in retained partitions which act as a common source for the persistent inflammation of the skull base and frontal recess with a polypoid formation [9–13].

Anatomical landmarks

The potential for complications in revision endoscopic sinus surgery (RESS), is higher than in primary FESS due to the altered anatomy and postoperative scarring [14]. At this point understanding the residual anatomy is crucial, for this reason, indeed its mandatory to have a new preoperative CT scan and if necessary also an MRI to address the post-surgical anatomical variations. In many cases, there are no landmarks present which make the surgery more difficult as the surgeon has to create the landmarks. However, fortunately, some anatomical landmarks are present despite previous surgeries like choana, nasopharynx, eustachian tube, posterior septum, nasal floor. Other landmarks like sphenoid ostium, maxillary sinus ostia, medial orbital wall (lamina papyracae), floor of the orbit, skull base at the level of olfactory cleft, bony nasolacrimal duct and the remnant of the middle turbinate at its anterior superior attachment are obscured by the recurrent inflammatory process, osteitis and scarring which may need to be designated and create new landmarks to proceed with the surgery [14, 15]. The identification of the constant landmarks starting at the posterior part of the sinonasal cavity identifying the roof of the choana, posterior nasal septum leads to identification of sphenoid sinus ostium which is usually located medial to the posterior insertion of the superior or supreme turbinate as shown in Fig. 1a, b. Once the sphenoid ostium is opened and enlarged, three dimensional orientations will perform to the posterior wall of the nasopharynx, the skull base, and the medial orbital wall, as shown in Fig. 1c [14–16]. Anteriorly identifying the attachment of the anterior superior remnant of middle turbinate with the posterior edge of lacrimal bone which saw as a prominent convexity on the lateral wall is help maintain orientation as shown in Fig. 2a. The middle turbinate attachment marks the boundary between ethmoid complex and the septum where the floor of the cribriform plate is vulnerable to penetration at this point as in Fig. 2b, the bulge or convexity created by the nasolacrimal duct is a constant valuable landmark to locate the maxillary sinus main ostium as well as the frontal sinus recess [14, 15]. The maxillary sinus ostium is a crucial landmark in the revision surgery as an integral part of the dissection between anterior and posterior sinus groups, in addition to, the lamina papyracea lies just superior to it and guides the surgeon along the most lateral portion of the dissection with protecting the eye from inadvertent injury. The border between the superior aspect of the maxillary ostium and the inferior edge of the lamina papyracea forming a ridge which represents the level of the floor of the orbit, is a useful landmark in identification, locating of the posterior ethmoid and sphenoid sinuses, where the most of the posterior ethmoid is located above and most of the sphenoid sinus below it as shown in Fig. 2 [14–17].

Fig. 1.

a Normal anatomical landmarks at the posterior part of the nasal cavity demonstrating, choana (CH), septum (SEPT), eustachian tube (ET), nasopharynx (NP), middle turbinate (MT), inferior turbinate (IT), lateral wall (LW), nasal floor (NF). b Showing the site of the sphenoid ostium (SPO) in between the posterior part of the septum and the tail of the superior turbinate (ST). c the sphenoid ostium is opened and enlarged, demonstrating the sphenoid sinus posterior wall (SSPW), sphenoid sinus roof (SSR), sphenoid sinus lateral wall (SSLW), performing a three dimensional orientations to the posterior wall of the nasopharynx, the skull base, and medial orbital wall

Fig. 2.

a *demonstrate the attachment of the anterior superior remnant of the middle turbinate (MT) with the posterior edge of lacrimal bone where the nasolacrimal duct (NLD) and sac (NLS) located and seen as a prominent convexity on the lateral wall, SEPT(septum). b The middle turbinate attachment marks the boundary between the anterior ethmoid roof (AER) and the septum (SEPT), FSP (frontal sinus pathway), MT (middle turbinate). c showing the level of the sphenoid sinus (SS) and the posterior ethmoid sinus (PES) in relation to the floor of the orbit which is marked by * which represent the border between the superior aspect of the maxillary sinus (MS) ostium and the inferior edge of the medial orbital wall (MOW), a yellow color imaginary line from the * to the septum demarcating the SS from the PES

Surgical Technique Instructions (Pearls and Pitfalls)

Two inverse techniques were introduced in the 1980s. The one promoted by Messer–klinger [17], who practiced the anterior-to-posterior approach. The other one, developed by Wigand [18] who performed posterior-to-anterior dissection, opens the sphenoid ostium or removes the anterior wall of the sphenoid sinus and ends with a total ethmoidectomy. Hereby in RESS start the dissection in posterior-to-anterior fashion by identification of the fixed landmarks to allow a quick easy orientation to the skull base and medial orbital wall as described below in the following steps:

1. Identifying the Choana: start the surgery by using a 0º endoscope, whenever polyps obstructing visualization of the choana, follow the nasal cavity floor during resecting the polyps with the micro-debrider until the choana seen in their entirety with the nasopharynx, eustachian tube, and the posterior septal wall.

2. Identifying the sphenoid sinus ostium: At the time of reviewing the Ct scan, it's vital to recheck it in three- dimensional views concentrating mainly on axial view and looking for the following:

1. Anatomical configuration and the pneumatization.

2. Site of the ostium to the tail of the superior turbinate.

3. Sphenoid inter-sinus septum usually ends at or adjacent to ICA which is dehiscent in 23% specially in hyper pneumatized sinus [2].

4. The optic nerve can course freely in hyper-pneumatized sinus and may be related to the posterior ethmoidal cells, especially if Onodi cell present [19]

5. Sever bony osteitis may be in contact with the important neurovascular structure, render us to touch it.

In locating the sphenoid ostia, the following possibilities might be seen:

• Ostia is visible (paraseptal location); as shown in Fig. 3a, before enlarging the ostia, rescue flap elevation just below the ostium at the level of the posterior end of the superior or supreme turbinate to preserve the septal branch of sphenopalatine artery of the nasoseptal flap for any further surgery that might need flap reconstruction.

• Ostia is not visible; as in Fig. 3b, ascend between the tail of supreme or superior turbinate and the septum, using J curette or mushroom punch forceps to find and open the ostia, whenever it's hard bony due to osteogenesis or osteitis then use a drill with copious irrigation.

• Ostia is lateralized; drill over the rostrum which defined by drawing an imaginary horizontal line from the tail of the supreme or superior turbinate to the septum intersect with a vertical line drown from the floor of the septum as shown in Fig. 3c, d and demonstrated in video 1.

• No ostium visible with no regional landmarks: using the level of maxillary sinus ostium as a landmark because it is at the same height level of the sphenoid ostium, otherwise using navigation image guidance is helpful.

Fig. 3.

Endoscopic sphenoidotomy in RESS a Visible sphenoid sinus ostium (SSO) in para-septal location, medial to the tail of the superior turbinate (ST) and lateral to the posterior end of the septum (SEPT), MT (middle turbinate). b Ostia is not visible; using mushroom and ascend between the tail of supreme or superior turbinate (ST) and the septum (SEPT) to enlarge the ostium, CH (choana). c Ostia is lateralized; showing the site of the drilling over the sphenoid rostrum (SR) (which defined by drawing a horizontal line (yellow color) from the tail of the supreme or superior turbinate (ST) to the septum, intersect with a vertical line (green color) drown from the floor of the septum, MT (middle turbinate), CH (choana). d showing trans-rostral approach to the sphenoid sinus (SS), CH (choana)

By accessing the sphenoid sinus through its natural ostia, enlarging the ostium inferiorly, laterally, superiorly and gathering a three dimensional orientation (depth, height, and width) with developing new landmarks which are the posterior wall, the roof (part of the skull base) and the lateral wall of the sphenoid sinus where it is in continuation with the medial orbital wall (orbital apex) as shown in Fig. 1c.

3. Identifying and opening the natural maxillary sinus ostium: During the reviewing of the Ct scan, it's vital to look for the anatomical configuration of the maxillary sinus, site of the infraorbital nerve, retained haller cell, maxillary ostium lying level to the medial orbital wall whenever it is in a lateral position will predispose to the orbital penetration. When the ostia not visible, try to rely on the constant landmarks or creating a new one as in the following scenarios.

A. Obvious bony NLD; follow the prominent convexity of the NLD down to its contact level with the superior margin of the inferior turbinate, as well as identified, the natural ostium lies just behind it, probe and enlarge it. When there is a retained piece of the uncinate process, probe and medialize the posterior end of the uncinate process, then insert the backbiter forceps into infundibulum with gentle traction in a superior medial direction, will pulls the retained uncinate further more medially then resect it by a forceps or using a micro-debrider, later on by using a cutting through an instrument, connect the natural and the accessory ostia together. In avoiding injury to the nasolacrimal duct, care must be taken not to force the instrument too much anteriorly.

B. Bony NLD landmark can’t be identified; either follow the hasner’s valve at inferior meatus superiorly in ascending fashion, define the bony nasolacrimal duct area then identifying the main ostium just behind it, or you can depend on the posterior fontanelle area in which can be identified in between posterior 1/3 of the inferior and middle turbinates where either of them is persist, opening and enlarge the posterior fontanelle accessory ostia and identifying the posterior maxillary wall with the medial margin of the orbital floor, then follow it till the anterior end where will encounter NLD, by connecting the posterior fontanelle with the natural ostium a medial maxillectomy type I will be performed. Care should be taken not to dissect too far inferiorly, to avoid transecting the lateral attachment of the inferior turbinate and inadvertent entry into the inferior meatus.

C. No any landmarks; you can depend on the following:

1. Stankiewicz maneuver (pushing the orbit and nasolacrimal duct in forward medial direction) to identify the NLD and lamina papyracae.

2. Level of the sphenoid sinus ostium and the floor, where it will be at the same level as the natural ostium.

3. Anterior canine fossa approach, by endoscopic assessment and irrigation through it, you can identify the sinus ostium and enlarge it later on.

By completing the above step, crucial new landmarks obtained, that helps in increasing the perception of dissection depth in relation to spheno–ethmoidal area, these landmarks are; (A.) Medial orbital wall.(B.) Orbital floor (C.) Posterior wall of the maxillary sinus, as shown in Fig. 2c.

4. Ethmoidectomy: The residual ethmoid cells are central to the other paranasal sinuses, and mostly entire ethmoid sinus cavities are involved in the disease process with underlying osteitic bone. Start to review the CT scan images of ethmoid skull base area considering;

A. Assessment of the ethmoid-skull base height and anatomical configuration depend on;

1. Keros classification for skull base height at nasal cavity roof, where type III according to Keros be in danger of violence.

2. The slope of the ethmoidal roof as a more shallow roof more prone to skull base injury.

3. The ratio of the maxillary–ethmoid height, if it is more than 2:1, means less room for dissection at the posterior ethmoid area with more possibilities of inadvertent skull base trauma.

4. Shape and thickness of the skull base on the sagittal plane need to take care when it resembles a hammock style because the posterior compartment will be higher than the middle compartment [20–23].

B. Notifying the osteitic changes in drilling near the vital structures like lateral lamella and anterior ethmoidal artery.

Ethmoidectomy is completed either in anteroposterior or in a reverse direction depending on the availability of the anatomical landmarks and the severity of the disease as in the following situations.

A. No landmarks: approach it posterio-anteriorly considering the skull base and medial orbital wall at the orbital apex as the main landmarks which are a superior and lateral extension of the sphenoid sinus [24]. With a careful look for pneumatization of sphenoid sinus, whenever there is a prominent lateral optico-carotid recess (OCR), means the ethmoid sinus roof start posteriorly at of sphenoid roof level, otherwise it will be above it if the onodi cell exists. The bony ethmoidal lamellar remnants resected using either through cut forceps after locating the free spaces behind the lamellar septation or drilling with irrigation in case of thickened or ostietic bone.

B. Obvious landmarks: proceed in anterio-posterior fashion considering the following anatomical landmarks; The superior attachment of the middle turbinate gives the medial dissection limit, lamina papyracea is the lateral dissection limit [25]. Start exposing the level of the skull base posteriorly at the posterior ethmoids which lies superior to the orbital floor level.

5. Frontal sinus surgery: Failure of the primary surgery may be due to missed frontal recess cells, retained superior portion of the uncinate process, lateralized middle turbinate remnants and neo-osteogenesis with polypoidal obstruction of frontal recess area [5, 25–27]. Once revision surgery is indicated, review the Ct scan and consider the following; In the sagittal plane: try to understand the relation between the agger nasi, bulla ethmoidalis and the variable recesses around it, and the thickness of nasofrontal beak. In the coronal plane: look for different configurations of the uncinate process insertion. In the axial plane: anteroposterior (AP) dimension of the frontal recess area to see wither its narrow or not, which may make the surgery difficult and risky, also measuring the medial to lateral dimension, as wide diameter gives more working space, especially for far lateral lesions. In revision frontal sinus surgery, you might have two scenarios according to the visibilities of the landmarks, as follow:

A. Obvious Landmarks: (Lateral to medial dissection technique); before starting the dissection, identify the following surgical landmarks: middle turbinate, NLD, a remnant of the cranial part of the uncinate process, anterior part of maxillary sinus main ostium, Lamina papyracea, remnant or unresected bulla, suprabullar cells and agger nasi.

Start with locating the cranial portion of the uncinate process then resects it with a cutting forceps, after that a cup-shaped remnant of bone will be identified (vertical bar) which allows the precise distinction between the sagittal portion of the middle turbinate and the lateral aspect of the cribriform plate (lateral lamella), then mobilizing it in mediolateral direction and resecting it with a cutting forceps prior to removal. This aids in preventing the incidental breaking of the lateral lamella and the stripping of the mucosa, the latter being considered the primary cause of post-operative stenosis obstructing the frontal sinus ostium. The lamina papyracea, considered a safe landmark needs to be identified to prevent orbital and skull base injury by continue dissection close and parallel to it especially at the corresponding level of the lateral lamella and be cautious that anterior ethmoidal artery runs at this area in a posteroanterior and lateromedial direction from lamina papyracea to the lateral lamella [28]. If the ethmoid bulla and supra-bullar cell fill the frontal recess due to high-grade anterior pneumatization, attempt to localize the anterior bony margin by proceeding from anterior to posterior, otherwise if the bulla not pneumatized and there is a working space between it and the agger nasi, proceed with an intact bulla technique by resecting the agger nasi in a posteroanterior direction with a through-cutting forceps before removing them. In this way, dissection can proceed without affecting the integrity of the underlying structures, which otherwise occurs if a traction (tearing) technique is applied, this dissection corresponds to Draf type I as shown in Fig. 4a [16, 29–31]. In the case of the frontal recess pathway not so clear, it is important to identify the NLD and the main maxillary ostium and trace up the pathway in between, this will access into the frontal recess area [25].

Fig. 4.

Endoscopic approaches in revision frontal sinus surgery a Demonstrate frontal recess clearance (Draf I), showing a cranial portion of the uncinate process (UP) and the frontal sinus (FS) pathway medial to it and in contact with the middle turbinate (MT). b Draf IIa showing resection the floor of the frontal sinus (FS) from the lamina papyracea to the middle turbinate (MT) level. c Draf IIb, left side frontal sinus (FS) floor resection from the lamina papyracea to the level of the nasal septum (SEPT) considering the level of the middle turbinate (MT) attachment to the skull base and the first olfactory fiber (black arrow) as a posterior landmark for access to the frontal sinus. d Median drainage procedure (Draf III) of the frontal sinus (FS) relay on first olfactory fiber and first anterior ethmoidal artery branch (black arrow) at the level of the skull base as posterior landmark for the drilling access into the frontal sinus, trimmed middle turbinate (MT) to the level of the skull base, resected upper part of the septum (SEPT)

Extended drainage procedures when needed are achieved by resecting the floor of the frontal sinus in between the lamina papyracea and the middle turbinate by using frontal cutting forceps, or further extending to the septum using drilling technique because the bone is thicker toward the nasal septum. Start by cutting through the anterior end of the middle turbinate till its attachment to skull base which corresponds to olfactory cleft level, then extend the area of the mucosal resection anterior to the axilla of the middle turbinate to remove the agger nasi cell completely. Proceed with drilling above and lateral to the axilla over the NLD bone to allow identification of the lacrimal sac which defines the anterior margin of the dissection. Later on, drilling in lateral to medial direction from the level of the sac till resection of the frontal sinus floor and the frontal beak, these techniques are corresponding relatively to Draf IIa and IIb as in Fig. 4b, c [16, 31]. Median frontal drainage (also known as the “modified Lothrop procedure”) is a well-known approach that consists of removing the frontal sinus floor from the lamina papyracea of one side to the lamina papyracea of the other side together with the inter-frontal septum passing through nasal septectomy and create a wide median drainage of the frontal sinus. Lateral to medial approach considered in the situation when the remnant of the landmarks for accessing of the frontal sinus  is visible, depending on the remnant of the superior portion of the anterior end of the middle turbinate as the main posterior limit of the dissection and nasolacrimal sac the anterior limit [32, 33]. Usually, try to find the middle turbinate remnant, if can’t be found, then try to follow the NLD and find the sac to reach the frontal pathway, as described in the following steps

1. Start by a cut through the superior portion of the anterior end of the middle turbinate till its skull base attachment, posteriorly at the level of the olfactory fibers on both sides and this is considered the posterior limit landmark.

2. Nasal septectomy: start with a horizontal incision through the septum, 5 mm below the inferior margin of the anterior end of the middle turbinate, extending up vertically through the septum up to the roof, then removing it by debrider, cutting instruments like a backbiter, and using drill over the bony part, until observing the tip of the middle turbinate on the opposite side.

3. Identify nasolacrimal sac as an anterior and lateral limit landmark and continue in the same way as mentioned above in Draf IIb to open each side separately. All previous steps can be done with 0º scope and straight drill.

4. After completing the resection of the floor of each sinus, start to connect them through removing the lower inter-frontal sinuses septum using angled 45º scope and angled drill.

5. Continue drilling through the anterior wall till it will be in smooth continuity of the nasal cavity and changing the shape from curvilinear to oval shape, and removing the bony projection of the skull base at the posterior wall of the sinus after identifying the first olfactory fiber. (7.) Finally getting the T shape configuration as in classical Draf III as shown in Fig. 4d [16, 31, 32].

B. No any landmarks: (Medial to lateral direction technique), as described below:

1. Identify the first branch of the anterior ethmoidal artery and first olfactory fiber by an inverted U shape incision in the roof of the nasal cavity starting 1–1.5 cm behind the remnant of the anterior end of the middle turbinate extending laterally over NLD area and medially over the superior part of the septum, this will be the posterior dissection limit as demonstrated in video 2. 2. Septectomy as its mentioned in lateral to medial approach.

3. Start to drill anterior to the posterior limit landmark in a medial to lateral direction toward the nasolacrimal sac until opening of the frontal sinus ostium then extend the resection till clear of the frontal recess as mentioned in previous approach, later on proceed to the contralateral side and lastly connecting both side as mention above in previous approach [16, 31].

4. Care is needed to ensure that the frontal sinus opening is bordered by bone on all sides and that the mucosa is preserved at least on one part of the circumference [29, 30].

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Conflict of interest

The authors declare that they have no conflict of interest.

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All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

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