INTRODUCTION
The first article confirming the feasibility and effectiveness of office-based balloon sinus dilation (BSD) procedures performed under local anesthesia was published in the peer-reviewed literature in 2011. Since that publication, several larger, multicenter clinical studies have established that BSD may be performed safely and comfortably in the office setting while yielding outcomes similar to the operating room. , These original studies sought to treat chronic inflammatory disease of the sinuses (CRS). More recently, the potential benefit of office-based BSD has been demonstrated for recurrent acute rhinosinusitis (RARS) as well. The Clinical Consensus Statement of the AAO-HNS published in 2018 includes both CRS and RARS as indications for BSD in the appropriate setting. Successful outcomes are dependent on appropriate patient selection, optimized local anesthesia, surgical technique grounded in anatomy and imaging study evaluation, and creation of an office procedure room that enables successful outcomes.
BSD of the Frontal Sinus Ostium
Inflammatory disease of the frontal sinus and frontal recess has traditionally presented a challenge for endoscopic sinus surgery. This is attributable to the location and surgical field such that the area is surrounded by the medial orbital wall (lamina papyracea), the fovea ethmoidalis posteriorly, and the frontal beak anteriorly. Ostial location at the terminus of the frontal recess makes visualization difficult as well. This anatomy makes balloon dilation techniques particularly beneficial as a first-line treatment in frontal sinus inflammatory disease that is unresponsive to medical management. Use of confirmatory image guidance as an adjunct in appropriate cases has expanded the role of BSD of the frontal sinus in the office setting.
Anatomical Considerations of the FSO
This begins with a thorough understanding of computed tomography (CT) scanning and endoscopic anatomy of the frontal sinus drainage pathway (FSDP), visualized by the surgeon in a three-dimensional perspective. The boundaries of the FSDP (also referred to as the frontal recess) are (1) the ethmoid bulla (plus suprabullar cells) posteriorly, (2) the lamina papyracea laterally, (3) the anterior superior attachment of the middle turbinate (MT) medially, and (4) the agger nasi (and frontal cells if present) anteriorly. , It is important to note the superior attachment of the uncinate process (UP) as this predicts the direction and location of frontal sinus drainage and the resulting orientation of the FSDP.
Specific Local Anesthesia for the FSO
Following surface or topical anesthesia of the nasal cavity and lateral nasal wall as detailed previously, infiltrative anesthesia with lidocaine 1% with 1:100,000 epinephrine at specific sites is carried out. First, injection of the lateral nasal wall superior to the anterior attachment of the MT is performed ( Fig. 13.1) . Next the MT is injected superiorly and inferiorly. This is followed by infiltration of the UP, especially superiorly. After medialization of the MT is performed, pledgets immersed in topical lidocaine 4% with epinephrine 1:100,000 are layered into the middle meatus with effort made to extend the pledgets into the superior compartment of the FSDP. These are maintained for 5 minutes. This allows for excellent anesthesia of the frontal recess and for achieving desirable hemostasis.
Injection of the lateral nasal wall superior to the attachment of the middle turbinate (MT).
Surgical Technique for the FSO
Study of the CT scans and development of a composite three-dimensional image of the actual FSDP should allow the surgeon to develop a search pattern strategy for the location of the natural FSO. The establishment of good anesthesia should lead to wide access to the middle meatus by gentle medialization of the MT. In cases where the UP attaches to the lamina papyracea and a more medial location of the inferior FSDP is predicted, the search will begin medially, anterior to the ethmoid bulla, and progress laterally toward the UP. In cases of reduced anatomical tolerance, the technique of sequential dilation is used. This technique uses the balloon catheter to dilate the inferior FSDP to progress more superiorly toward the FSO. Using tactile feedback and fiberoptic light demonstration with a wiper pattern manipulation, entrance into the FSO and FS is confirmed. Upon removal of the balloon device, observation of the ostial dilation and the frontal sinus dome should be apparent. If anatomically complex cases are foreseen, use of image guidance is encouraged, either with ostial seeker-guided probes or image-guided balloon catheters. Most image guidance systems have augmented reality capability to set up FSDP trajectory preoperatively and in real time if desired.
Balloon Sinus Dilation of the Sphenoid Ostium
Dilation of the sphenoid ostium (SO) represents an excellent tissue preservation technique for addressing mild to moderate or relatively isolated inflammatory disease of the sphenoid sinus. It may also be combined with a hybrid technique to expand the dilated ostium with instruments such as sphenoid punches or microdebrider when appropriate. The basis for successful BSD of the SO is centered on (1) anatomical knowledge, (2) local anesthesia to resolve patient discomfort and optimize hemostasis, and (3) surgical method to resolve safety concerns and enable successful treatment.
Anatomical Considerations for the SO
Familiarity with the practical surgical anatomy of the sphenoid sinus ostium (SSO) will allow for rapid identification of the target zone. Further, correlation with CT scanning with endoscopic visualization for individual cases will permit a successful and safe BSD. On average, the SSO resides 7 cm in a sagittal trajectory angled at 30 degrees from the nasal sill and at the apex of a vertical line drawn from the upper lip of the posterior choana. A useful concept is to visualize a right-angled triangle with the leg drawn at the medial boundary of the superior turbinate and the base at a right angle to the inferior attachment of the superior turbinate. The hypotenuse encloses the area of the triangle and forms the “search zone” of the SO, commonly referred to as Bolger triangle. Staying medial to the superior turbinate and starting inferiorly within this triangle should form the search pattern for the SO in performing BSD ( Fig. 13.2 ).
Staying medial to the superior turbinate and starting inferiorly within this triangle should form the search pattern for the SO in performing BSD.
Specific Local Anesthesia for the SO
The foregoing discussion is predicated on prior delivery of topical anesthesia as discussed in the anesthesia overview section. The central component of anesthesia for SSO dilation is the sphenopalatine (SP) nerve block. The authors prefer to perform this transnasally in the following manner. First, the MT is injected both at its superior attachment and inferiorly with lidocaine 1% and epinephrine 1:100,000 solution. This affords lateralization of the MT and allows access to the sphenoid rostrum. This area is then anesthetized topically (4% lidocaine and epinephrine 1:100,000) using pledgets. After 4 minutes, these are removed, and the site is ready for the SP nerve block. The authors’ preference is to use a 27-gauge spinal needle to deliver approximately 1 cc of local anesthetic to a site just medial to the attachment of the nasal septum to the sphenoid rostrum ( Fig. 13.3 ). This results in thorough and reliable anesthesia of the SO within 4 minutes. It also provides excellent hemostasis and anesthesia for the nasal airway structures, including posterior septum, posterior ethmoidal cells, and nasal floor.
