Chronic sinusitis - CASS FESS surgery
Effective treatment of chronic sinusitis – fast and gentle treatment with CAS FESS technique
Effective treatment of chronic sinusitis with a focus on safety and security
At Charlottenlund Private Hospital, some of Denmark's most experienced surgeons are ready to treat chronic sinusitis without waiting. Chronic sinusitis can cause symptoms such as long-term nasal congestion, headaches, facial pressure, reduced sense of smell and frequent sinus infections. If you suffer from these symptoms, treatment can be an effective solution to your problems.
At Charlottenlund Private Hospital, we have extensive experience in treating chronic sinusitis and have many years of expertise in the field, as well as brand new navigation equipment from German Fiagon. This ensures that safety and precision are top notch. The treatment is often covered by private health insurance.
How do you know if you need treatment for chronic sinusitis?
Chronic sinusitis can cause several symptoms, including:
✅ Long-term nasal congestion and difficulty breathing through the nose✅ Headaches and facial pressure✅ Reduced sense of smell✅ Frequent sinus infections that do not go away with antibiotics✅ Increased discharge from the nose, often yellow or greenish
If you experience one or more of these symptoms, an assessment by a specialist may be appropriate.
This is how chronic sinusitis is treated - CAS FESSCAS FESS stands for Computer Assisted Surgery and FESS stands for Functional Endoscopic Sinus Surgery. Today, the procedure is simply called ESS - or in Danish "endoscopic sinus surgery".
The treatment of chronic sinusitis with endoscopic sinus surgery varies depending on the severity and the patient. At Charlottenlund Privathospital we almost always perform the full operation, where all sinuses are opened and cleaned, and any drainage obstructions are removed. The operation is performed under general anesthesia and lasts between 60 and 120 minutes.
Aftercare and healing – what you need to know After the operation, you will be hospitalized for observation for a short period of time, after which you will be able to return home the same day. Most patients experience only mild discomfort in the first few days after treatment. Most can resume their daily activities after approximately 4-7 days.
Our specialist doctors ensure that you receive thorough information about the aftercare and pain relief on the day of surgery.
Book a consultation Are you experiencing symptoms of chronic sinusitis? Book an appointment with our specialists today and get a professional assessment. We ensure safe and secure treatment with the country's highest expertise.
📞 Contact us now – We are ready to help.
You can also read more about treating chronic sinusitis at sundhed.dk.
Sune writes on TrustPilot after having surgery by clinic manager Jacob Fisker in 2024:
"From the examination by Jesper Balle to the operation and follow-up examination. Short waiting time and highly professional staff. All the way through. I felt very safe and really well taken care of 🙏💚
And no - never nice to have surgery and the discomfort without pain afterwards. But hold on, it's been worth it 🙏 I'm deeply grateful to now be able to breathe through my nose. I only have high praise and thanks for Charlottenlund Private Hospital and the staff! Thank you 🙏💚"
Read also about:
Correction of a deviated nasal septum (septoplasty)
Surgery of the nasal concha (Conchotomy)
Treatment of nosebleeds
Frequently Asked Questions
What is chronic sinusitis?
The sinuses consist of the frontal, ethmoid, maxillary and sphenoid sinuses, which are cavities in the skull where inflammation can occur. The sinuses are connected to the nose, and when inflamed, these drainage passages become blocked. If the condition lasts more than 12 weeks, it is called chronic sinusitis.
The symptoms of chronic sinusitis are similar to those of a cold. With chronic sinusitis, you will experience a heavy feeling and tightness in the area around your nose, facial pain, reduced sense of smell, stuffy nose, runny nose and difficulty breathing. This is because the inflammation blocks the passages from your sinuses to your nose. You may experience the symptoms on one or both sides of your face.
How does chronic sinusitis occur?
Chronic sinusitis is a common condition that affects approximately 10% of the population. There are many causes of the condition, including allergies, narrow sinus passages, deviated nasal septum, smoking, nasal polyps, etc. In some cases, the cause cannot be found.
Acute sinusitis is an acute illness with pain and possibly fever and is caused by an infection. This typically occurs in connection with a cold and lasts a few weeks after which it goes away again. If you have many cases of acute sinusitis, in some cases you can be offered an operation to open the sinuses to prevent this.
Acute sinusitis usually resolves on its own within 7-10 days, but some people may experience persistent inflammation and mucus in their sinuses. If this condition lasts for more than 12 weeks, it is considered chronic sinusitis and should be treated medically or surgically.
Function of the sinuses
If you feel the forehead, on both sides of the nose and in the curve between the eyes and nose, you would think that the facial bone in these places is solid. However, it is not – between the outer and inner sides of the bone there is a cavity. This cavity is called a sinus.
It is not fully understood why we have sinuses at all. Some have suggested that the air-filled cavities are there to reduce the weight of the skull, while others believe that the sinuses act like a crumple zone in a car, so that trauma to the forehead and nose does not reach the brain. We know that sinus surgery does not affect the resonance of the voice, and they have no function for the nose.
Why choose Charlottenlund Private Hospital?
Safe and caring treatment by the staff present with minimal risk.
Charlottenlund Private Hospital has extensive experience with endoscopic sinus surgery. We offer:
- Experienced specialists with a high number of procedures performed. All surgeons have performed many hundreds of procedures independently.
- Minimal risk of complications – our surgeons attend several courses in endoscopic sinus surgery every year and travel around the world every year to improve their skills. This ensures that surgical techniques are constantly refined and that the surgeons' knowledge is kept up to date with new techniques, etc.
- Modern facilities and the latest equipment for optimal patient experience. In 2024, Charlottenlund Privathospital purchased the latest and most advanced navigation equipment from German Fiagon.

Pre-study
Once you have been diagnosed with chronic sinusitis and are scheduled for surgery, you will need to undergo a preliminary examination. The preliminary examination takes place at our private hospital in Charlottenlund, where the doctor examines your sinuses with a brief endoscopic examination and a review of the CT scan of your sinuses.
The endoscopic examination can often determine the cause of your chronic sinusitis. Is it due to, for example, nasal polyps, large turbinates, a deviated nasal septum, or something else? The doctor can easily determine this with the help of the endoscopic examination and CT scan. If surgery is required for nasal polyps, large turbinates, or a deviated nasal septum, this will be agreed in advance.
The study also shows whether, due to the anatomy, there will be challenges in accessing the sinuses during surgery.
Operation
Surgery for chronic sinusitis is performed under general anesthesia and takes approximately 1.5 hours. The surgery may take longer if surgery is also required for nasal polyps, large turbinates, or a deviated nasal septum.
The operation aims to create permanent drainage from the sinuses and into the nose by expanding the natural drainage from the sinuses. It is performed through the nostrils and using advanced 3D computer navigation equipment, the so-called CAS FESS technique. Since no two patients are the same, the way in which drainage is created may differ from patient to patient. The procedure is determined by the surgeon during the preliminary examination.
After surgery, a short sick leave may be required, but most people are ready to go to work within a week.
Book an appointment for treatment of chronic sinusitis
If you suffer from chronic sinusitis and would like to be treated with us, please feel free to contact us. Our secretaries are ready to help and answer any questions you may have, as well as to find time for both a preliminary examination and surgery.