FESS Up! You Need a Sinus Surgery Refresher

Good documentation and a thorough understanding of anatomy and procedures will help you accurately code this service.

By Laurette Pitman, RN, CPC-H, CGIC, CCS

Anyone who has had chronic sinus infections knows how miserable the constant headache and facial pressure can be. Fortunately for chronic sufferers, there is a minimally invasive surgical technique to help alleviate this problem. Today, functional endoscopic sinus surgery (FESS) is the primary approach used for the surgical treatment of chronic sinusitis. Familiarity with the procedure and sinus anatomy aids in the accurate selection of CPT® codes for this service.

Start with the Procedural Basics

FESS is performed under direct visualization to restore sinus ventilation and normal function. Indications and ICD-9-CM codes for FESS include:

  • Chronic sinusitis refractory to medical treatment (473.9 Unspecified sinusitis (chronic))
  • Recurrent sinusitis (473.9)
  • Nasal/sinus polyps (471.9 Unspecified nasal polyp and 471.8 Other polyp of sinus)
  • Sinus mucoceles (478.19 Other disease of nasal cavity and sinuses)
  • Foreign body removal (932 Foreign body in nose)
  • Epistaxis control (784.7 Epistaxis)

Prior to the procedure, the physician performs a thorough history and examination, a trial of medical treatment, and a computed tomography (CT) scan (70486 Computed tomography, maxillofacial area; without contrast material). The CT scan is mandatory to identify the patient’s ethmoid anatomy and its relationship to the skull base and the orbits, along with the extent of the sinus disease.

In a typical FESS procedure, the physician first identifies the middle turbinate and removes the uncinate process to expose the ethmoid bulla. The anterior ethmoid air cells are opened, leaving the bone covered with mucosa. This allows for better ventilation of the anterior ethmoid sinuses. The maxillary ostium is examined and, if it is obstructed, a middle meatal antrostomy is performed. This minimal surgery is often sufficient to improve the function of the osteomeatal complex, which improves the ventilation of the maxillary, ethmoid, and frontal sinuses.

If the CT scan shows disease in the additional sinuses, the endoscope is advanced further into these areas. Additional endoscopic procedures may include sphenoidotomy, frontal sinus exploration, and removal of localized irreversible disease in the maxillary sinuses. If indicated, septoplasty and inferior turbinectomy may also be done during the surgical encounter.

Select CPT® Codes by the Treated Location

Thorough and accurate physician documentation is the key to correct FESS code selection. CPT® provides multiple codes in the Sinus Endoscopy subsection to report these procedures, dependent on the sinuses surgically treated. CPT® also includes extensive instructions in this subsection, so become very familiar with these notes.

CPT® codes 31231-31297 describe diagnostic and surgical endoscopic sinus procedures. All of the codes report unilateral procedures, with the exception of 31231 Nasal endoscopy, diagnostic, unilateral or bilateral (separate procedure), which specifies unilateral or bilateral in the descriptor. If any other procedure in this code range is provided bilaterally, append modifier 50 Bilateral procedure. For unilateral procedures, anatomic modifiers RT Right side and LT Left side are used to identify the site of surgery.

The surgical codes for endoscopic sinus procedures describe interventions where the sinuses are manipulated, opened, and pathologic tissues are removed. These codes always include any diagnostic inspection performed prior to or concurrently with the surgical intervention.

Surgical treatment of the ethmoid sinus cells is a more common component of endoscopic sinus surgery. Because ethmoid sinuses are divided into anterior and posterior regions, CPT® has defined two separate codes for reporting these procedures. For drainage of infected mucous and removal of inflamed tissue confined to the anterior ethmoid cells, report 31254 Nasal/sinus endoscopy, surgical; with ethmoidectomy, partial (anterior). When both the anterior and posterior regions are treated, assign 31255 Nasal/sinus endoscopy, surgical; with ethmoidectomy, total (anterior and posterior). Both 31254 and 31255 include removal of any polyps encountered and a middle turbinectomy. A medically necessary inferior turbinectomy may be reported separately with either 30130 Excision inferior turbinate, partial or complete, any method or 30140 Submucous resection inferior turbinate, partial or complete, any method, depending on the technique.

Antrostomy generally is defined as making an opening into the maxillary sinus for drainage. This procedure commonly is performed with an endoscopic ethmoidectomy and assigned 31256 Nasal/sinus endoscopy, surgical, with maxillary antrostomy for the maxillary antrostomy. A more extensive procedure, which involves removal of tissue from the maxillary sinus(es), is used to treat polyps, redundant mucous membrane, fungal debris, or bony partitions, and is reported with 31267 Nasal/sinus endoscopy; with removal of tissue from maxillary sinus. This procedure includes antrostomy, and may be performed alone or with other endoscopic sinus interventions.

During frontal sinus exploration (31276 Nasal/sinus endoscopy, surgical with frontal sinus exploration, with or without removal of tissue from frontal sinus), the physician creates a permanent opening from the frontal sinus to the nose. The complexity of this procedure is determined by the site of obstruction to the outflow tract, disease within the sinus, or variations in frontal and ethmoid sinus anatomy, but the same code will always apply. The surgery focuses on removing the obstructing disease and restoring drainage.

Disorders of the sphenoid sinus are likely underreported, both because they are unusual and due to lack of recognition. Headache is the most common symptom, and may be caused by inflammation or expansile lesions of the sphenoid sinus. During sphenoidotomy, an opening is created into the anterior or front wall of the sinus to allow for improved drainage. Select 31287 Nasal/sinus endoscopy, surgical, with sphenoidotomy for this procedure. For a more extensive procedure, which would involve removal of tissue from the sphenoid sinus, assign instead 31288 Nasal/sinus endoscopy, surgical, with sphenoidotomy; with removal of tissue from the sphenoid sinus.

Stereotactic Navigation Calls for Additional Coding

An important component of FESS is the use of the stereotactic computer assisted navigation (61782 Stereotactic computer-assisted (navigational) procedure; cranial, extradural). This image guidance provides for the navigation and localization of high-risk anatomical areas adjacent to the sinuses, such as the optic nerve. In its guidelines for “Intraoperative Use of Computer Aided Surgery,” the American Academy of Otolaryngology gives the following examples as indications for use of the navigational system:

  • Revision sinus surgery
  • Distorted sinus anatomy
  • Extensive sino-nasal polyposis
  • Pathology involving the frontal, posterior ethmoid and sphenoid sinuses
  • Disease abutting the skull base, orbit, optic nerve or carotid artery
  • Cerebrospinal fluid (CSF) rhinorrhea or conditions where there is a skull base defect
  • Benign and malignant sino-nasal neoplasms

Clinical coding example: A 56-year-old male with a history of chronic sphenoid sinusitis presents with chronic headaches. A CT scan shows opacification in the sphenoid sinus and bilateral ethmoid sinus disease.

Findings: Polyps and pus in the sphenoid sinuses were seen, along with green thickened debris in the lateral aspect of the right sphenoid sinus. Mucosal swelling in the ethmoid air cells and osteitic bone was noted. Maxillary sinuses were free of disease.

Procedure: The patient is taken to the operating room (OR) and general anesthesia is induced. The LandmarX image guided head frame is placed on the patient’s forehead and her anatomy is calibrated to within 2 mm accuracy. The right side of the nose is addressed first. Via transethmoid approach, a sphenoidotomy is created. Polyps and pus are found within the sinus. The microdebrider is used to remove polyps and diseased mucosa. Pus is irrigated.

Total right ethmoidectomy was then performed under image guided assistance. Air cells were seen along the skull base and some osteophytic bone. This was all removed. The left side was addressed and identical procedures were carried out. The sinus cavity was then irrigated with dilute hydrogen peroxide and suctioned clear. Afrin pledgets were placed into the nasal cavity and tied in front of the columella.

Sponge and needle count was accurate. The patient was then awakened from general anesthesia, extubated, and transferred to the recovery room in stable condition.

CPT® code assignment for this example includes:

  • 31255-50 for the documentation of the bilateral total ethmoidectomies
  • 31288-50 for the sphenoidotomy with removal of polyps and tissue from the sphenoid sinuses
  • 61782 for the LandmarX navigational procedure

Use Dedicated Codes for Balloon Sinuplasty

CPT® 2011 established three codes to report endoscopic dilation of the sinus ostia. Code 31295 Nasal/sinus endoscopy, surgical; with dilation of maxillary sinus ostium (eg, balloon dilation), transnasal or via canine fossa describes endoscopic dilation of the maxillary sinus ostium, either transnasally or via the canine fossa. Both CPT® and the National Correct Coding Initiative (NCCI) consider 31295 to be an inclusive component of 31256 Nasal/sinus endoscopy, surgical, with maxillary antrostomy and 31267 Nasal/sinus endoscopy, surgical, with maxillary antrostomy; with removal of tissue from maxillary sinus. Do not report 31295 separately when performed on the same sinus as either 31256 or 31267.

To report balloon dilation of the frontal sinus ostium, turn to 31296 Nasal/sinus endoscopy, surgical; with dilation of frontal sinus ostium (eg, balloon dilation). Instructional notes indicate this code is not reported with 31276 when performed on the same sinus.

Finally, for balloon sinuplasty of the sphenoid sinus ostium, report 31297 Nasal/sinus endoscopy, surgical; with dilation of sphenoid sinus ostium (eg, balloon dilation). Per CPT® instructions, do not report 31297 with 31235 Nasal/sinus endoscopy, diagnostic with sphenoid sinusoscopy (via puncture of sphenoidal face or cannulation of ostium), 31287, or 31288 when performed on the same sinus.

CPT® guidelines that accompany 31295-31297 indicate that fluoroscopy, if used, is an inclusive component of these codes and should not be separately reported. Also, as with the other endoscopic sinus procedure codes, these codes report unilateral procedures unless otherwise specified.

Clinical coding example: A 66-year-old patient with chronic maxillary sinusitis who has failed medical management presents for bilateral balloon dilation of the maxillary ostium. The patient is taken to the OR, where general anesthesia is administered and an intranasal vasoconstrictive agent is injected. Using the endoscope, a guidewire is introduced transnasally into the right maxillary ostia. A balloon is then passed over the guidewire and introduced into the maxillary ostia. The position of the guidewire and balloon are confirmed via endoscope. The balloon is inflated, which displaces bone and mucosa and results in dilation of the right maxillary ostia. The balloon is then deflated and removed. The procedure is repeated in the left maxillary ostia. The documented procedure is reported as 31295-50.

Learn Your Way Around the Sinuses

The paranasal sinuses are air-filled pockets located within the bones of the face and around the nasal cavity. There are four pairs, each named for the bone in which it is located:

  • Maxillary sinuses – located in the cheekbones under the eyes
  • Ethmoid sinuses – 6-12 small sinuses per side, located between the eyes
  • Frontal sinuses – located in the forehead
  • Sphenoid sinuses – behind the ethmoid sinuses, near the middle of the skull

Each of these sinuses has an opening, called an ostium, connecting it to the nose

In the lateral wall of the nose are the superior, middle, and inferior turbinates. Each turbinate is a rounded projection that extends the length of the nasal cavity.

The inferior turbinate (the largest of the three) runs parallel to the floor of the nose.

The middle turbinate is part of the ethmoidal bone and projects from the lateral wall of the nasal cavity. It is just above the middle meatus into which the anterior ethmoid cells open. The middle turbinate and the middle meatus together represent the key area of the nose, known as the osteomeatal complex (OMC).

The superior turbinate, located above the middle turbinate, is the smallest of the turbinates and is not commonly associated with significant sinus disease.

The nose also contains the nasal septum, which divides it into two nasal cavities. The most common diagnosis involving this anatomic area is a deviated septum (ICD-9-CM 470 Deviated nasal septum), in which the top of the cartilaginous ridge leans either to the left or the right, causing an obstruction of the affected nasal passage. The condition can result in poor drainage of the sinuses.


Laurette Pitman, RN, CPC-H, CGIC, CCS, is an outpatient consultant for Laguna Medical Systems, the coding and compliance service area of Springfield Service Corporation. She has over 30 years’ experience in the health care field, including ED and OR nursing, coding, and DRG and APC auditing. For more information, go to www.lagunamedsys.com or contact Ms. Pitman at laurpitman@cox.net.



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