Over three decades ago, Walter Messerklinger developed endoscopic sinus surgery in Graz, Austria. Prior to this advancement, sinus surgery was an “open” surgery that required skin incisions. These incisions were hidden under the lip, in skin creases, or behind the hairline. This approach is now called external sinus surgery.
External sinus surgery is now typically used only in special circumstances. It is done to better see or reach areas that cannot be accessed through the nose alone. Indications include trauma of the facial bones and sinuses, severe infections, and large tumors. This technique is most often used to enter the maxillary sinus, ethmoid sinus, or frontal sinuses (See Sinus Anatomy). The common procedures used for these locations will be discussed below.
When And How External Procedures Are Used
Caldwell-Luc Approach: This approach was the most common type of sinus surgery from 1900 until about 1990. There are parts of the maxillary sinus that are still hard to see or reach even with the tools available today. A Caldwell-Luc approach can be used to enter directly through the front wall of the maxillary sinus. An incision is made under the upper lip where it meets the gum line. The tissue is lifted off the bone in this area. Then, an opening is made directly through the front wall of the maxillary sinus. This approach can help to see or access hard to reach areas like the floor or front wall of the sinus. Once the procedure is completed, the incision under the lip is closed with dissolvable stitches.
External ethmoidectomy: An external approach to the ethmoid sinuses is done through a small skin incision between the bridge of the nose and the eye. The scar from the incision can be extremely well hidden using various plastic surgery techniques. In general, ethmoidectomy is typically performed through the nose now. However, the external technique can still be useful in certain circumstances. One such situation is a serious sinus infection which causes an abscess (pocket of pus) in the eye. External ethmoidectomy may also be useful during a severe nose bleed. Stopping some severe nosebleeds may require clipping of the anterior ethmoid artery. The external approach may be appropriate in this instance. Both of these operations can be accomplished endoscopically. However, the tools and specialized team needed may not always be available to every surgeon. Sometimes, these types of procedures are also urgent. In such a scenario, the external approach may be the safer and quicker solution. In addition, the external approach is sometimes used by skull base surgeons when removing tumors.
Frontal sinus trephination: This surgical approach is still somewhat commonly used in specific circumstances. Perhaps the most common circumstance involves the need to access the outermost aspects of the frontal sinus. Reasons include a pocket of trapped mucous (called a mucocele), severe infection (called an abscess) and sinus tumors. In these cases, a frontal sinus trephination creates an opening directly through the forehead into the frontal sinus. The approach is accomplished through a 1 cm incision just under the eyebrow. These incisions typically heal well and the scars can be camouflaged by the brow. A small opening is then made through the bone under the incision and into the sinus. Endoscopes and other instruments are introduced through this window to reach all corners of the sinus.
Frontal sinus osteoplastic flap: This operation involves opening the entire frontal sinus from the outside. It is performed by making an incision through the scalp at the top of the head and behind the hairline if possible. The frontal sinus is then outlined before any cuts through the frontal bone are made. Traditionally, this was done using an X-ray film of the sinus. Now, CT-guided navigation (See Image-Guided Surgery) is often used to mark the outlines of the sinus. The surgeon can then cut through the bone at these edges and open the entire front wall of the sinus. Surgical instruments can be used to address problems like tumors or fractures. This approach is still used in severe trauma where bone fragments have obstructed the sinus. If the natural drainage cannot be restored, an osteoplastic flap can be performed to make the sinus non-functional so that it no longer produces mucus. In this scenario fat or similar tissue is used to fill the sinus cavity (called frontal sinus obliteration). In circumstances where the inner wall of the frontal sinus is severely fractured, this wall can also be fully removed and the brain allowed to expand into the sinus. This is called cranialization. Finally, in some cases of scarring of the frontal sinus drainage tract caused by prior surgery, an osteoplastic flap approach and frontal sinus obliteration may be recommended. Despite the extensive nature of the operation, the cosmetic outcome is often quite good with scars being hidden behind the hairline.
The risks, complications, and alternatives of external sinus surgery are similar to those of endoscopic sinus surgery (See Complications of Sinus Surgery). Given that external approaches require external incisions, visible scars can result. Also, temporary or permanent facial numbness from stretching or cutting of sensory nerves can rarely occur. Facial asymmetry may result from some of these approaches but is highly unusual. Specific to the Caldwell-Luc is the low risk of damage to a tooth or a persistent opening between the mouth and sinus, called an oroantral fistula, which could require revision surgery. Benefits pertain to the specific conditions for which the surgery is being planned.
Follow-up visits for these procedures are similar to follow-up for endoscopic sinus surgery. However, after frontal sinus osteoplastic flap surgery and external ethmoidectomy surgery, a hospital stay of one or more nights may be recommended. Typically, any stitches that require removal would be removed at about 7 to 10 days after surgery.
Despite great advances in modern endoscopic surgical techniques, there is still a role for external sinus surgery in certain circumstances. External approaches may be used on their own or in addition to endoscopic techniques to provide access to difficult-to-reach sinus locations and to help resolve complex problems.
Copyright © 2020 by the American Rhinologic Society