This review discusses extended endoscopic and open sinus surgery for refractory chronic rhinosinusitis. Extended maxillary sinus surgery including endoscopic maxillary mega-antrostomy, endoscopic modified medial maxillectomy, and inferior meatal antrostomy are described. Total/complete ethmoidectomy with mucosal stripping (nasalization) is discussed. Extended endoscopic sphenoid sinus procedures as well as their indications and potential risks are reviewed. Extended endoscopic frontal sinus procedures, such the modified Lothrop procedure, are described. Extended open sinus surgical procedures, such as the Caldwell-Luc approach, frontal sinus trephine procedure, external frontoethmoidectomy, frontal sinus osteoplastic flap with or without obliteration, and cranialization, are discussed.
Key points
- •
Chronic recalcitrant maxillary sinusitis may require extended sinus surgery for adequate management, including the endoscopic maxillary mega-antrostomy and the endoscopic modified medial maxillectomy. The sublabial anterior maxillotomy is an external approach that can also be used in these patients.
- •
Revision total ethmoidectomy should be considered in refractory chronic rhinosinusitis with the goals of resection of all remaining ethmoid partitions, removal of all osteitic bone, and potential ethmoidal mucosal stripping (nasalization) to prevent recurrence.
- •
Chronic recalcitrant sphenoid sinusitis may require an extended sphenoid sinusotomy with creation of a single, large common cavity. This decreases the potential for scarring and obstruction and provides a large pathway for application of topical medications.
- •
A variety of extended endoscopic endonasal and open frontal sinus procedures can be used in the management of refractory chronic frontal sinusitis. The goal of these endoscopic procedures is to create a patent nasofrontal outflow tract (frontal sinus drainage pathway) as an egress pathway and to provide access for application of adequate topical medications. The external approaches can be used to preserve frontal sinus function or to obliterate the frontal sinus. Cranialization of the frontal sinus represents the final remedy in treatment of recalcitrant frontal sinusitis.
| AMT | Appropriate medical therapy |
| BCD | Balloon catheter dilation |
| CSF | Cerebrospinal fluid |
| EMMA | Endoscopic maxillary mega-antrostomy |
| ESS | Endoscopic sinus surgery |
| IGS | Image-guidance surgery |
| MCLP | Modified central-Lothrop procedure |
| MHLP | Modified hemi-Lothrop procedure |
| MLP | Modified Lothrop procedure |
| MMLP | Modified mini-Lothrop procedure |
| MSLP | Modified subtotal-Lothrop procedure |
Video content accompanies this article at http://www.oto.theclinics.com .
Introduction
Over the past 3 decades, the management of patients with chronic rhinosinusitis (CRS) has evolved from significantly invasive procedures to minimally invasive mucosal-preserving options. Currently, the overwhelming majority of patients with CRS can be treated effectively with appropriate medical therapy (AMT). For patients who failed AMT, the next option is surgical intervention. Initial surgical treatment usually involves endoscopic sinus surgery (ESS) with maximal mucosal preservation; this can be achieved using balloon dilation technology or functional ESS. In cases of failed initial surgical treatment, revision ESS using more aggressive techniques is often undertaken. Nonetheless, a subgroup of patients will go on to fail revision treatment with traditional ESS techniques. In these situations, more advanced surgical procedures may be necessary for extirpation of the disease process. In this article, the authors describe advanced surgical techniques used for the maxillary, ethmoid, sphenoid, and frontal sinuses in patients with refractory CRS who have failed AMT and traditional ESS techniques.
Introduction
Over the past 3 decades, the management of patients with chronic rhinosinusitis (CRS) has evolved from significantly invasive procedures to minimally invasive mucosal-preserving options. Currently, the overwhelming majority of patients with CRS can be treated effectively with appropriate medical therapy (AMT). For patients who failed AMT, the next option is surgical intervention. Initial surgical treatment usually involves endoscopic sinus surgery (ESS) with maximal mucosal preservation; this can be achieved using balloon dilation technology or functional ESS. In cases of failed initial surgical treatment, revision ESS using more aggressive techniques is often undertaken. Nonetheless, a subgroup of patients will go on to fail revision treatment with traditional ESS techniques. In these situations, more advanced surgical procedures may be necessary for extirpation of the disease process. In this article, the authors describe advanced surgical techniques used for the maxillary, ethmoid, sphenoid, and frontal sinuses in patients with refractory CRS who have failed AMT and traditional ESS techniques.
Extended maxillary sinus procedures
In his 1675 volume Dissertationes anatomico-pathologicae , the renowned anatomist Antonio Molinetti reports a case of maxillary sinusitis that was successfully treated via trephination through the anterior maxillary sinus wall. More than 2 centuries later, 3 surgeons would independently publish descriptions of a technique that became the standard for the next one hundred years: George Caldwell (in 1893), Scanes Spicer (in 1894), and Henry Luc (in 1897) each described the creation of a temporary opening through the canine fossa and a simultaneous counter-opening in the inferior meatus. This procedure came to be known as the Caldwell-Luc operation.
In the latter part of the twentieth century, advances in the understanding of maxillary sinus physiology, as well as the advent of new surgical technologies, would eventually lead to the development of so-called functional ESS.
Today, the initial management of chronic maxillary sinusitis is nonsurgical; surgery is reserved for cases whereby AMT has failed to achieve disease resolution. When an intervention is warranted, 2 major options exist: either balloon catheter dilation (BCD) or endoscopic endonasal maxillary antrostomy. BCD is an endoscopic procedure in which the sinus ostium is identified, cannulated with a balloon catheter, and dilated. Endoscopic maxillary antrostomy entails resection of the uncinate process followed by widening of the maxillary sinus ostium. In both cases, the goal is to establish patency of the maxillary sinus by widening its natural aperture, which should preserve the native mechanism of mucus egress (hence the designation of “functional” surgery).
Despite its high success rate, maxillary antrostomy failure is not uncommon. In a study of patients undergoing revision ESS, for instance, middle meatal antrostomy stenosis was found in 39% of cases. Multiple factors have been implicated in the development of persistent (or recalcitrant) maxillary sinusitis, including impaired mucociliary clearance (eg, in cystic fibrosis or primary ciliary dyskinesia), biofilm formation, and previous endoscopic or open surgery.
Endoscopic Maxillary Mega-Antrostomy
In 2008, Cho and Hwang described their experience with a less extensive form of salvage surgery: the endoscopic maxillary mega-antrostomy (EMMA). EMMA entails a partial inferior turbinectomy (ie, with preservation of at least its anterior one-third) and widening of the maxillary antrostomy down to the level of the nasal cavity floor ( [CR] ). This configuration allows for gravity-assisted drainage of a sinus in which mucociliary clearance has been rendered ineffective. It also facilitates irrigation, topical medication delivery, and access for in-office surveillance. In a follow-up to the aforementioned 2008 study, the original 28-patient cohort reported either complete/significant improvement (72.4%) or partial improvement (27.6%) after a mean follow-up period of 6.9 years.
Endoscopic Modified Medial Maxillectomy
Although sometimes conflated in the literature, EMMA must be differentiated from the endoscopic modified medial maxillectomy (EMMM), an extended procedure that was originally conceived for the management of benign sinonasal neoplasms. In contrast to EMMA, EMMM entails a complete inferior turbinectomy and widening of the antrostomy to its anatomic limits: inferiorly, to the level of nasal cavity floor; superiorly, to the medial orbital floor; posteriorly, to the posterior wall of the maxillary sinus; and anteriorly, to the nasolacrimal duct. EMMM allows ample access to the maxillary sinus, including difficult-to-reach areas such as the lateral recesses, the posterior aspect of the anterior maxillary sinus wall, and the floor of the maxillary sinus ( [CR] ). In essence, in recalcitrant maxillary sinusitis, the indications for EMMM and EMMA are the same. The preservation of normal tissue that EMMA provides is desirable, but not always feasible. Moreover, in EMMM, widening of the antrostomy anteriorly may place the nasolacrimal duct at risk of injury. During the EMMM for chronic recurrent sinusitis, auto-obliteration of the sinus may be the goal. In this situation, a decision can be made to completely eradicate the maxillary sinus mucosa and trigger the natural obliteration of the sinus ( Fig. 1 ).
Endoscopic-Assisted Sublabial Anterior Maxillotomy
After the introduction of ESS, the Caldwell-Luc operation remained an option for surgically refractory maxillary sinusitis. Sublabial maxillotomy is performed rarely these days for inflammatory disease; however, endoscopic-assisted sublabial anterior maxillotomy remains an option for disease that is otherwise difficult to reach endonasally ( Fig. 2 ).
Inferior Meatal Antrostomy
Widespread understanding of paranasal sinus physiology has caused another technique, the inferior meatal antrostomy, to fall out of favor. Hence, although the inferior meatal antrostomy provides a pathway for egress of maxillary sinus contents, this opening does not incorporate the natural ostium of the maxillary sinus where the mucociliary flow of this sinus converges. Consequently, there is a belief that this procedure could lead to mucous recirculation and prevent eradication of the disease process. Nevertheless, some have argued for its role in managing postoperative mucoceles, stating that it is effective and “easier to perform” than middle meatal antrostomy. This procedure can be performed alone, or in combination with a middle meatal antrostomy ( Fig. 3 ). The inferior meatal antrostomy (similar to the EMMA and the EMMM) can be useful in cases of improper mucociliary clearance due to ciliary dysfunction such as primary ciliary dyskinesia (also known as Kartagener syndrome or immotile ciliary syndrome), or abnormally viscous mucous secretions, as seen in patients with cystic fibrosis .
Extended ethmoid sinus procedures
CRS often involves the ethmoid sinuses. When surgery is indicated, the standard contemporary approach is an endoscopic resection of the affected compartments (ie, the anterior ethmoid sinus and/or the posterior ethmoid sinus, which lies beyond the basal lamella). The principle of mucosal preservation applies: diseased tissue is removed and sinus patency is established, but healthy-appearing mucosa is spared whenever and wherever it is feasible. The preservation of healthy-appearing mucosa should, in theory, result in better postoperative function. However, this may not always hold true. There are situations in which a minimalist approach may in fact yield inferior postoperative outcomes.
Complete Total Ethmoidectomy with Mucosal Stripping
One such example is CRS with extensive polyposis. In 1997, Jankowski and colleagues presented results of a retrospective study comparing conventional ethmoidectomy to a procedure termed nasalization ( Fig. 4 ). Nasalization, or radical ethmoidectomy, is defined by the investigators as the act of “systematically removing all the bony lamellae and mucosa within the [ethmoid] labyrinth, with large [maxillary] antrostomy, sphenoidotomy, frontotomy, and middle turbinectomy.” In this study, patients who underwent nasalization showed superior improvement in nasal symptoms relative to those who underwent more limited ethmoidectomy. Olfactory improvement remained stable for 3 years in the nasalization group and worsened after 2 years in the ethmoidectomy group. In a 2006 follow-up to this study, Jankowski and colleagues found nasalization to be superior in terms of overall symptoms (as assessed by a questionnaire), endoscopic appearance of the mucosa, appearance on computed tomography, and total recurrence rate (22.7% in the nasalization group vs 58.3% in the traditional ethmoidectomy group).
External Frontoethmoidectomy
The external frontoethmoidectomy has been largely supplanted by ESS. In the management of ethmoid sinusitis, its role is essentially limited to the management of complications, as in the case where an anterior ethmoid artery ligation is necessary or for the management of an orbital abscess (the latter more commonly in the setting of acute rhinosinusitis). A detailed discussion of this procedure in the context of external frontal sinus surgery can be found below.
Extended sphenoid sinus procedures
In the setting of inflammatory disease, the sphenoid sinus is accessed surgically via one of 2 routes: the transnasal (or direct) route and the transethmoidal route. The latter technique is usually used when inflammatory disease also involves the posterior ethmoid sinuses. Similar to the Draf classification for frontal sinus surgery, a classification scheme has been proposed for sphenoid sinus surgery. According to Simmen and Jones, a type I sphenoidotomy entails identification of the ostium without further intervention; a type II sphenoidotomy entails enlargement of the ostium upward to the level of the cranial base, and inferiorly to one-half of the sinus height; and a type III sphenoidotomy involves widening the ostium to its most lateral extent.
In general, more extensive sphenoid sinus surgery is reserved for cases wherein the disease process is extensive or previous surgery has failed. In some cases, a bilateral extended sphenoidotomy is necessary. In this procedure, the posterior aspect of the nasal septum is resected, along with the sphenoid rostrum, the intersinus septum, and other intrasphenoid partitions ( [CR] ), creating a common cavity with a broad drainage pathway. It also allows access to the lateral recesses of this sinus for removal, for instance, of large mucoceles, fungus balls, or extensive polyposis. The resulting cavity is essentially identical to that which is created by endoscopic transsphenoidal pituitary surgery, for which positive sinonasal outcomes have been widely reported.
Extended frontal sinus procedures
In patients with chronic frontal sinusitis that have failed AMT, management consists of frontal sinusotomy via either BCD or other limited frontal sinusotomy such a Draf I or Draf IIA. However, in cases of recalcitrant frontal sinusitis or recurrent disease after a previous frontal sinus procedure, a variety of extended endoscopic endonasal and open frontal sinus procedures can be used. The objective of the endoscopic procedures is the creation of a patent nasofrontal outflow tract (frontal sinus outflow pathway) and to provide access for application of topical medications. These endoscopic frontal sinus procedures include the Draf IIB, the modified Lothrop procedure (MLP), and 4 modifications of the MLP. The external approaches can be used to preserve frontal sinus function as well as for frontal sinus obliteration. These external approaches are the frontal sinus trephine procedure, the external frontoethmoidectomy, and the frontal sinus osteoplastic flap with or without obliteration.
Extended endoscopic frontal sinus approaches
Draf IIB
A Draf IIB procedure may be viewed as the least extensive extended endoscopic frontal sinusotomy. This procedure has previously been described in the literature as a Nasofrontal approach type III, or Eloy type IIB procedure. In this type of frontal sinusotomy, the frontal sinus outflow tract is enlarged by resecting the frontal sinus floor from the nasal septum medially to the ipsilateral lamina papyracea laterally ( [CR] ). After this procedure, unilateral maximal opening of the frontal sinus outflow tract is achieved. This procedure is indicated primarily after failure of Draf I or Draf IIA procedures, or in primary refractory frontal sinusotomy cases with difficult anatomy. In a recent retrospective chart review, Turner and colleagues found this procedure to be most commonly used in revision cases of chronic frontal sinusitis secondary to lateralized middle turbinate remnant, frontal sinus mucocele, or postoperative synechiae. The long-term patency of the created frontal sinusotomy in this cohort of patients was found to be greater than 90% after a mean follow-up of 16.2 months.
Modified Lothrop Procedure
The MLP (also termed an endoscopic modified Lothrop procedure, Draf III, nasofrontal approach type IV, or Eloy type III procedure) consists of bilateral removal of the floor of the frontal sinus from one lamina papyracea to the contralateral lamina papyracea. In this procedure, a superior septectomy, intersinus septectomy, and resection of other frontal sinus partitions are also performed. By creating contiguous bilateral enlargement of the frontal sinus drainage pathway, this procedure provides the largest frontal sinus opening achievable ( [CR] ). This procedure can be used after failure of Draf I, Draf IIA, or Draf IIB procedures, or in primary refractory frontal sinusotomy cases with challenging anatomy. In 1998, Casiano and Livingston reported the University of Miami’s initial experience with the MLP in 21 patients. In that study, they found an overall patency rate of 90% after a mean follow-up of 6.5 months. In 2006, Banhiran and colleagues reported the University of Miami’s experience using the MLP with stenting using a silastic sheet in 72 patients. The investigators could endoscopically visualize a common ostium in 94% of the cases (61.1% patent and 33.3% stenotic) after a mean follow-up of 22 months. In a recent (2014) retrospective cohort study by Naidoo and colleagues that included 229 patients undergoing MLP with a mean follow-up of 45.0 months, the investigators achieved a success rate of 95% with no further surgery being required. This same group of investigators later analyzed the failure rate of revision MLP and found it to be 21%. They also noted that intraoperative purulence at the initial MLP, more than 5 previous sinus surgery, and aspirin-exacerbated respiratory disease increased the risk of failure. In a 2003 systematic review on the MLP, Scott and colleagues found that the evidence base for MLP was inadequate to assess its safety and efficacy. In 2009, Anderson and Sindwani performed a systematic review and meta-analysis to assess the safety and efficacy of the MLP in 612 patients that met the inclusion criteria for their study. The investigators reported frontal sinus patency or partial stenosis in 95.9% of the patients at last follow-up. They found a rate of minor and major complications of less than 1% and 4%, respectively.
Modified Lothrop Procedure Modifications
Recently, several modifications to the MLP have been described for select cases in order to address specific anatomic and pathologic challenges of frontal sinus disease while decreasing morbidity. These modifications include the modified hemi-Lothrop procedure (MHLP), the modified mini-Lothrop procedure (MMLP), the modified subtotal-Lothrop procedure (MSLP), and the modified central-Lothrop procedure (MCLP).
Modified hemi-Lothrop procedure
The MHLP (also termed Eloy type IIC procedure) is a technique described to increase access to the far lateral frontal sinus recess (supraorbital extension) or a supraorbital ethmoid cell. In this procedure, a superior septectomy is added to an ipsilateral Draf IIB. This superior septectomy opening permits insertion of the endoscope and instruments via the contralateral nasal cavity, therefore providing greater access and visualization of the lateral frontal sinus recess of the affected ipsilateral frontal sinus or supraorbital ethmoid ( Fig. 5 ). In this procedure, binostril and bimanual instrumentation can be performed for better disease eradication. Unlike in the MLP, the contralateral frontal sinus floor, recess, and frontal intersinus septum are preserved. The contralateral middle turbinate is also left untouched. This procedure has only been recently described, and data on its long-term efficacy are scarce. In a 2012 technique paper involving 15 patients (14 of which had CRS), a 100% success rate was reported for the MHLP after a mean follow-up of 18.2 months.
