Endoscopic surgery for chronic sinusitis. Surgery to treat sinusitis: everything you need to know about surgery Minor surgery: puncture and its alternative - balloon sinusoplasty

About how serious such a disease as sinusitis, probably, everyone knows today. Not only is such inflammation accompanied by a host of unpleasant symptoms that seriously impair a person’s quality of life, but also its complications can be extremely dangerous to health and even life.

If you do not start timely treatment or treat the disease incorrectly, there is a high risk that the functioning of the organs of vision and hearing will deteriorate, lung pathologies will develop, meningitis or even sepsis will begin.

In the early stages of the disease, it is possible to cope with it through local therapy. A little later, you have to connect antibiotics. When the results of conservative therapeutic methods do not live up to expectations, it is likely that an operation is prescribed for sinusitis.

The operation is considered an extreme, but the most effective method of treating sinusitis.

So, there are cases when the operation, indeed, is the most effective treatment option for sinusitis. Here are the main indications for this:

• if conservative therapy, which involves taking antibiotics, sprays and undergoing physiotherapy procedures, has not resulted in positive results;
• if there are secondary complications that are caused by chronic suppuration in the sinuses;
• with the formation of complications inside the skull or infected cysts;
• in the case of a closed form of inflammation of a chronic nature;
• if the infection could spread beyond the boundaries of the maxillary sinuses;
• if something in the sinuses prevents breathing through the nose.

However, it is worth mentioning the contraindications to surgical procedures, which depend on:

• the general condition of the patient;
• the ability of the body to endure the intervention of a surgeon;
• diagnosing endocrine diseases;
• problems with the hematopoietic system;
• development of inflammatory processes.

These contraindications are either permanent or temporary. And the final decision on the operation is made by the doctor.

History and modernity

Interestingly, for the first time, sinus surgery for sinusitis was mentioned back in the 17th century. A detailed description of such a procedure in the middle of the 19th century was compiled by the American surgeon Caldwell (a little later - by the surgeon Luc from France).

Naturally, today the treatment methods and instruments have improved markedly, but the basics of surgical intervention and, of course, the indications have remained the same.

The operation, by the way, is called the most effective treatment for inflammation of the maxillary sinuses due to the fact that it involves the complete cleansing of the sinus from pus, after which the inflammatory process stops. In addition, it turns out to be effective in cases where conservative treatment does not help or is pointless (for example, if there is a filling material in the sinus after dental treatment).

Modern medicine does everything necessary to minimize the harm - functional as well as cosmetic - caused to the patient during surgery. Therefore, options such as endoscopic treatment have appeared, when the scars from the incisions made are only inside the cavity, that is, they are absolutely not visible externally.

In addition, there is ongoing development of local anesthetics with a minimum of allergic reactions and a minimum of detrimental effects on the kidneys and liver.

Puncture

Speaking about the surgical treatment of sinusitis, first of all, a nose puncture, that is, a puncture, comes to mind.

This is the least secure option, but the procedure itself is quite simple. Sometimes it is even considered as a therapeutic and diagnostic manipulation, since its implementation provides the opportunity to:

• get the contents of the sine;
• examine it and determine the microorganisms that caused the disease, to which antibiotics they are sensitive.

How is this operation done for sinusitis?

• Use local anesthesia or anesthesia (at the discretion of the doctor).
• The maxillary sinus is pierced with a special needle.
• The purulent contents are removed from it.
• Wash the sinus with an antiseptic.

Even the first such procedure brings a noticeable positive effect. But more often than not, multiple procedures are needed. In order not to pierce the sinus each time, a nylon catheter is inserted into the resulting hole, due to which the wound does not heal, and subsequent washings are carried out through it.

When five washes have been done, and the inflammation is still not cured, more serious surgical therapy will be needed.

People are often very afraid of such surgical treatment of sinusitis, they are very nervous in anticipation of the procedure. But, despite the fact that there may be certain side effects, there is nothing complicated and extremely dangerous in it: any otolaryngologist in a hospital of a medium-sized city in our country annually performs up to five thousand such operations.

Balloon sinusoplasty

How else is sinusitis removed? Balloon sinusoplasty can be considered an atraumatic intervention, which aims to open and expand the natural fistulas connecting the nose to the paranasal sinuses.

• It will require the use of flexible catheters and atraumatic guidewires that can pass through the tortuous nasal structures without damaging them.
• The catheter is inserted into the nasal cavity, after which its cuff is inflated, and the diameter of the anastomosis increases.
• The sinus is washed with an antiseptic.

The main difference between this treatment option and the puncture is associated with the absence of damage to the nasal structures, although the results can be achieved the same. There will also be no cosmetic defect. But if the procedure does not lead to positive results, then, as already indicated, a more serious approach to treatment will be needed.

Yamik catheter

Removal of sinusitis is possible through the use of a Yamik catheter. The presented method is also not associated with damage to the anatomical structure of the nose.

A sinus catheter is, first of all, three tubes: moreover, two of them have cuffs.

• To prepare the nasal cavity, it is treated with an anesthetic and a vasoconstrictor is instilled there (this will reduce swelling).
• After the introduction of the catheter tubes into the nostrils, the cuffs inflate and delimit the nasal cavity from the pharynx, forming a space in which a vacuum is created.
• Thus, the accumulated secret comes out of the sinus more easily.
• When the contents are aspirated, the sinus is treated with an antiseptic and washed.

Such an operation can be easily carried out in any clinic - if there was a YAMIK catheter, no other equipment would be needed.

Endoscopy

Of the sparing, but radical options for therapy, endoscopic surgery to remove sinusitis can be noted.

In this case, you will need equipment such as an endoscope, that is, a special fiber-optic tube with a pair of channels on the sides, into which work items are inserted, such as clamps, scissors, coagulators.

The main advantage of this intervention is associated with the ability of the surgeon to observe the entire sinus cavity - accordingly, he can remove all the tissues that have been affected by the inflammatory process, while maintaining the maximum amount of healthy tissue. The removal of purulent contents is also visually controlled.

Thus, at one time it is possible to achieve the desired goal.

laser procedure

Another type of endoscopy is laser surgery for the treatment of inflammation of the maxillary sinuses.

Everything, in principle, is the same as mentioned above, only the working instrument fed through the endoscope is a laser.

Such radiation affects the mucosa with a certain intensity and at a certain frequency. As a result, heating and even superficial microburning occur. In this case, pain is absent.

One procedure, as a rule, is not enough, however, carrying out several such manipulations allows you to achieve the following effects:

• reduction in mucosal volume;
• improved aeration by the sinus;
• improvement of blood circulation;
• activation of immunity;
• removal of inflammation.

Not every clinic, of course, has the equipment for such treatment.

Operation Caldwell-Luc

Surgical treatment of sinusitis may involve the so-called Caldwell-Luc operation.

By the names in the name of this surgical intervention, you can guess that this is how the inflammation of the maxillary sinuses was treated by those who first suggested doing it surgically.

Today, such methods can be resorted to in cases where:

• more sparing therapeutic options were ineffective;
• there are irreversible changes associated with the mucosa (this happens with fungal, odontogenic or cystic inflammation).

Here is how such manipulation is carried out:

• The patient is under anesthesia and, of course, in a supine position. He is cut into the area of ​​\u200b\u200bthe skin just below the upper lip where the sore sinus is located.
• A hole is made with a special chisel to open access to the sinus space.
• Pus and mucosa, affected by pathological inflammation, are removed.
• The sinus is treated with an antiseptic and antibiotic.

As you can see, this option cannot be called atraumatic, since cosmetic defects are possible after the operation, and the wound will heal for a long time.

After surgery

So, the surgical treatment of sinusitis has been carried out and you are already close to recovery. But in order to avoid any complications, a certain postoperative therapeutic course will be needed, which involves taking medications that are usually prescribed for the conservative treatment of inflammation:

• antibiotics;
• glucocorticosteroid drugs;
• vasoconstrictors;
• immunomodulators.

When deciding to have an operation (and often such a treatment option is resorted to as an extreme method, when all other methods have already been tried), you must be prepared for the fact that there may be certain consequences. Of course, this is not necessary, but their occurrence cannot be ruled out.

Much, by the way, is determined by:

• what method of surgical intervention is chosen;
• how correctly the technique of sinus surgery is observed (in the video you can see that this procedure requires the surgeon to observe a lot of nuances);
• what qualifications and experience the doctor has, and what equipment is available in the clinic (alas, state clinics do not always have tools that meet high quality and the latest requirements);
• whether rehabilitation measures have been taken.

And immediate complications after manipulation can be as follows:

• incessant bleeding;
• development of secondary infection;
• decreased sensitivity of the operated areas of the face (area of ​​the upper lip and nose);
• impaired sense of smell;
• visual impairment;
• fistula formation.

It is very important, for example, to carry out oral hygiene procedures after surgery. In addition, regular rinsing with antiseptics is necessary (all the more, this is required after a radical maxillary sinusectomy or Caldwell-Luc operation has been performed).

Be sure to take all medications prescribed by your doctor. Sometimes people believe that this or that remedy prescribed by an otolaryngologist can be missed, but such omissions will lead to serious trouble later.

In the near future after the treatment of the maxillary sinuses by surgery, it is necessary to regularly appear for a medical examination so that the doctor can observe how everything heals and whether a recovery has really been achieved.

ENT surgeons at SM-Clinic perform all types of operations, but in most cases they prefer microsurgical maxillary sinusotomy as the safest and most effective method.

Microsurgical maxillary sinusectomy

Microsurgical technique

General anesthesia

Operation time - 30-60 min

The cost of the operation: from 40,000 rubles *

Microsurgical microgeniotomy. The surgeon makes a small - 4 mm - hole in the anterior wall of the maxillary sinus. Access to it is carried out under the lip, from the vestibule of the oral cavity, above 4-5 teeth. Under the control of a microscope with different viewing angles and with the help of micro-instruments, the doctor conducts an audit of the sinus cavity and performs the necessary manipulations: removes pus, cysts, polyps or a foreign body, rinses the cavity with a medicinal solution. After the maxillary sinusectomy, the access hole is sutured. Within a few days, there may be a slight swelling of the cheek tissues on the access side.

Microsurgical endonasal maxillary sinusectomy. In this case, access to the maxillary sinus is carried out without punctures. The doctor expands the natural or forms an artificial anastomosis in the region of the middle or lower nasal passage and introduces a microscope and microinstruments into it. Further manipulations are similar to those performed during microsurgical micromaxillary sinusectomy.

If there are contraindications to microsurgical intervention, the Center's ENT surgeons perform a classic operation.

Radical maxillary sinusectomy according to Caldwell-Luke.

General anesthesia

Operation time - 10-15 minutes

Time of stay in the hospital - 1 day

The cost of the operation: from 20,000 rubles. *

(excluding the cost of anesthesia and hospital stay)

Radical maxillary sinusectomy according to Caldwell-Luke. With the classical method, the surgeon makes a 5-6 cm incision in the mucosa under the upper lip to the bone and pushes the tissue to the side. Then, using a drill or chisel, a hole is made in the anterior bone wall of the sinus for the introduction of instruments. After that, the doctor installs drainage through the fistula into the middle nasal passage, removes purulent contents from the sinus, and rinses the cavity. The operation is completed by suturing the mucosal incision.

As a rule, all types of maxillary sinusectomy in the Center are performed under general anesthesia (endotracheal anesthesia). If there are contraindications to this type of anesthesia, the patient's desire or small volumes of surgery, we use local anesthesia.

Our specialists are high-level professionals with impressive experience in surgical interventions and are fluent in classical and modern methods of performing operations.

* the indicated prices are preliminary and may change if additional services are required, the price also does not include a preoperative examination.

Believe me: endoscopic operations are much safer than those done before for the treatment of similar problems. It is not so traumatic, blood loss is minimal, recovery is 2-3 days. Perhaps your case is not as neglected as mine, and then you should not worry all the more.

If you want everything to go as smoothly as possible:

1. Do not spare time for a complete examination - CT and MRI

2. Consult with different doctors (run away from those who, without looking at the picture, immediately draw conclusions)

3. If you are very worried - do not spare money for a good full anesthesia (But! Only high-quality - more at the end of the review)

4. Ask to be inserted into the nose after surgery hemostatic sponges and not tampons or worse, a bandage!

"Nerves are to blame"

I have never had any special problems with immunity, rarely got sick. But for the past three years, I've stopped recognizing myself. Eternal temperature 37 and red throat. I went around the doctors of all paid clinics in Moscow. They just didn’t say something, including that you see, the nerves are to blame))). Meanwhile, I started having a protracted sinusitis ...

Punctures are not a panacea

Many are prescribed punctures and some even help. BUT, remember! X-rays are not enough to send a person for this procedure. Do an MRI to identify the real cause of sinusitis. The puncture then did not lead to anything, water poured from the nose and that's it. However, the doctor did not guess that complaints about pressure and the absence of mucus are not just signs of sinusitis. Without properly understanding and not taking the appropriate pictures, he sent me for an operation. I refused.

Thank God, I managed to find an adequate doctor when I came to Anapa for treatment. He immediately said that he needed an MRI. The same evening, a large cyst was found in the right sinus. At first there was a shock - the operation is inevitable. But, I learned about endoscopic operations on the Internet and became a little calmer.

A bit of mysticism

I went to Krasnodar for a consultation. All the way I prayed that the doctor would make the right decision. And this must happen. It was on this day that the anesthesia machine broke down, and the doctor called everyone to reschedule the operation for a month.

Barely looking at the pictures, he replied that the reason was the partition. "But please," I replied. She never bothered me before. I had sinusitis six months ago, before that there were no problems. "Yes, and the summary for the MRI clearly states: the curvature is not large. But the doctor said that only septoplasty would help.

Surprise

I was not ready to wait another two months. I was tormented by a headache (more precisely, pressure) and a lack of oxygen. I went to Moscow. At the Institute of Neurosurgery, Burdenko was immediately told that MRI was not enough. CT scan (computed tomography) revealed the filling material in the other sinus. A few years ago, the therapist filled the canals and did not keep track (the therapist, in principle, should not do this), they did not provide me with any pictures then. And then the filling began to overgrow with fungi and bacteria, and eventually turned into a large dense fungus.

About the operation

Let me tell you straight away: I am a terrible coward. She exhausted both herself and her family with excitement. Tenoten helped to restrain her emotions. But my surgeon Marina Vladislavovna helped me finally forget about fear. Not a drop of indifference, only a desire to help and set up for a speedy recovery.

The surgeon explained that even if it is not possible to get a cyst and a filling endoscopically (they are too large), they will make a micro-incision above the lip, which is also not very scary (the tiny scar heals quickly).

They suffered with me for three hours, but EXPERIENCE and ENDOSCOPY won! Managed to get everything.

About anesthesia

Already on the eve of the operation in the evening it is better not to eat so that the next day the stomach is empty. This subsequently helped to avoid nausea from anesthesia. I was anesthetized with propofol. (After reading the ENT forums, I insisted on sevoran) and for three hours in a dream I was engaged in choosing New Year's gifts for relatives))) I woke up from the fact that the nurse called by name and said "breathe". Anesthesia did not give any clouding of consciousness, I clearly understood everything and woke up very quickly, as if from a normal dream. Why general anesthesia is preferable for ENT operations was convincingly expressed by mig17 on the loronline forum.

What to take to the hospital?

The first night was not painful, it was just unpleasant. A friend who went through a similar experience a year ago said that the torments are hellish, but this is not so. You can survive the night with sponges in your nose, although it is unpleasant. For another day I had blood clots coming out of my throat and nose. My throat was swollen and a little sore. This is normal after anesthesia. Ask for painkillers or suck on lidocaine lozenges. A teaspoon of peach oil will also help relieve pain. Edema helped me to remove Telfast from allergies a little.

Hemostatic sponges

The next day, one hemostatic plug was pulled out, and part of the other came out only after weeks of regular rinsing with Dolphin. The hemostatic sponge does not injure the sinuses, unlike conventional tampons. Comes out easy. And even if a particle got stuck in the nose and they could not get it, there is no need to panic - it will come out or resolve (they write that in 3-6 weeks).

Possible Complications

I read reviews, many have numbness of the lips or teeth. I had numbness in my two front teeth. But! it was before, but not as strong. They say it was because the cyst was pressing on a nerve. The numbness decreased after half a month, now I almost don’t feel it - everything is in order.

Almost a month after the operation, I can say that the improvement has certainly come. The constant fever and headaches are gone. Although the nose sometimes gets clogged (not all the pus has come out yet), but not for long - I forgot about the vasoconstrictor drops.

Good luck to everyone, and God bless!

In the treatment of sinusitis, the otolaryngologist will prescribe many medications (antibiotics, decongestants, nasal steroid sprays, sinus ointment, antihistamines) and procedures (in particular, sinus lavage).

There are cases when the doctor and the patient find out that the infection does not respond to drugs and there is no outflow of mucus through the nasal passages. When this happens, the option to get rid of sinusitis becomes a surgical procedure. With its help, you can increase the holes through which mucus flows from the maxillary sinuses.

Very few people need surgery to treat sinusitis.

But you may need sinus surgery if:

• The doctor says that you have chronic sinusitis.
• You followed what is called "maximum medical treatment" for 4 to 6 weeks. This means that you have been taking prescription and over-the-counter medicines at home as directed by your healthcare provider.
• You have had a computed tomography (CT) scan after 4 or 6 weeks of treatment. This is very important so that the specialist has an idea of ​​what might be causing your infection. For example, a CT scan may show polyps in the nose, which are an obstacle to the normal outflow of mucus.

You may also need surgery for sinusitis if:

• You have a sinus infection caused by a fungus. It cannot be eliminated with antibiotics for sinusitis.
• You have a serious problem, such as an infection that spreads outside of your sinuses. This happens rarely.

Surgery may be limited to removing diseased tissue or small growths (polyps) inside the nose. A more extensive operation involves removing part of the bone to create a wider opening.

Options for sinus surgery include:

Functional endoscopic sinus surgery (FEHS). Developed in 1950, the endoscope procedure revolutionized sinus surgery. In the past, the strategy was to remove the entire mucosa of the major sinuses.

The use of the endoscope has been linked to the theory that the best way to get a normal, healthy sinus is to open up natural pathways to the diseased sinus. After an improvement in the drainage system is achieved, the mucosa of the infected sinus has the opportunity to return to normal functioning.

FEHP involves inserting an endoscope, a very thin fiber optic tube, into the nose for direct visual inspection of the opening in the maxillary sinuses. Obstructive tissues are removed with the help of modern instruments. In most cases, the surgical procedure is performed exclusively through the nostrils, leaving no external scarring. After it, there is only a slight swelling and mild discomfort.

Operation Caldwell-Luc. Helps to get rid of chronic sinusitis by improving the drainage of the maxillary sinus, one of the cavities under the eye. First, the maxillary sinus is opened through the front wall and polyps, affected mucous and purulent masses are removed. Then the cells of the ethmoid bone are opened and the affected tissues are removed in the upper medial angle of the maxillary sinus. At the next stage, the surgeon imposes an anastomosis between the sinus and the lower nasal passage.

This maxillary sinus surgery is most often performed when a malignant tumor is present in the sinus cavity.

Sinus puncture with sinusitis. It is performed under local anesthesia.

Using a syringe needle, an otolaryngologist pierces the bony septum between the nasal passage and the maxillary sinus.

Then the syringe washes the sinus with saline.

At this time, the patient should open their mouth and lean forward to allow the contents of the sinus and saline (see also saline composition) to flow out through the mouth.

Surgery for sinusitis: a reminder for the patient and potential risks

Surgery for sinusitis allows you to remove the diseased or obstructive sinus tissue, which leads to improved drainage of the contents of the sinuses. At the same time, postoperative care is as important as the operation itself.

One of the most common reasons for this procedure to fail is poor postoperative care and failure to follow the surgeon's recommendations.

• Before the operation, the patient must refrain from eating and drinking for 8 hours.
• On the day of the operation, the patient must have all the necessary medical certificates and meet with the anesthesiologist. He should only take medicines approved by the surgeon and anesthesiologist.
• The operation may take several hours.
• After sinus surgery, most patients can return home accompanied by a friend or relative. They will be prescribed bed rest (preferably lie with your head up). Apply an ice pack to the painful area to prevent bleeding.
• Recovery after sinus surgery can take 3 to 5 days; during this time, patients should take their prescribed medications and avoid any physical activity.
• Tell your surgeon if you experience excessive bleeding, fever above 38.6 C that persists even with anti-inflammatories, acute pain or headache that does not respond to medication, increased swelling of the nose or eyes, and clear fluid from the nose.
• Self-medication and prevention of complications include maximizing nasal moisture (frequent moistening of the nose with sprays) and avoiding contact with people with colds and influenza.

The following complications of sinus surgery have been reported in the medical literature. This list does not purport to be comprehensive and does not include all possible complications of sinus surgery.

• Bleeding. In very rare cases, a blood transfusion may be required.
• Chronic drainage of mucus, excessive dryness or crusting in the nose.
• Need for further and more invasive surgical procedures.
• The need for allergy treatment or environmental control to prevent other sinus problems. Surgery is not a panacea and will not replace allergy treatment.
• Failure to improve or relieve concurrent (with sinusitis) respiratory conditions such as asthma, bronchitis, or cough.
• Failure to treat sinus-related headache. The exact cause of headaches can be difficult to determine. The patient or doctor may need to consult with another specialist, such as a neurologist.
• Damage to the eye and related structures.
• Injury to the base of the skull, resulting in meningitis, brain abscess, or leakage of cerebrospinal fluid.
• Permanent numbness of the upper teeth, palate or face.
• Nasal congestion due to inability to control infection or polyps.
• Prolonged postoperative pain.
• Loss of smell or taste.

The surgeon analyzes the risks and benefits of surgery when obtaining consent for the operation. The patient can always discuss with him the possibility of these complications and, if necessary, choose another method of treating sinusitis.

Inflammation of the maxillary sinuses requires systemic treatment. Doctors use conservative and surgical techniques. During therapy are prescribed:

• antibiotics;
• steroid ointments and aerosols;
• regular flushing of the sinuses through the nostrils;
• antihistamines.

If therapy does not help, the doctor cleans the maxillary sinuses by endoscopic method. To do this, a resection is performed, a tube with a camera and medications are inserted into the incision made. The doctor observes the condition of the sinuses on the monitor and can remove the accumulated discharge from all hard-to-reach places.

Sinus cleansing surgery

During the operation, the surgeon removes all neoplasms in the sinuses, minimally injuring the soft tissues. The endoscope camera allows you to perform the operation with high accuracy.

The surgeon must conduct a preliminary examination of the patient and identify all his individual characteristics before cleaning the sinuses. The operation is performed by experienced surgeons with extensive practice. Most often, washing the sinuses is required for their acute inflammation. Otherwise, the inflammatory process can move to other vital areas of the body.

Often indications for surgical cleaning are:

• exacerbation of sinusitis;
• getting a foreign object into the nostril;
• acute rhinitis, leading to the accumulation of disease-causing fluids in the sinuses;
• polyps or cysts.

By flushing, you can improve the quality of breathing, eliminate the exacerbation of chronic diseases, and prevent the spread of inflammation.

Cleaning of the maxillary sinuses by endoscopic method in the clinic "First Surgery"

The clinic "First Surgery" is ready to perform any operation to remove a cyst or polyp during the cleaning of the maxillary sinuses, as well as the fluid accumulated in them. This surgical technique was created in 1950 and today has not lost its significance in medicine.

With its help, you can get rid of chronic congestion, exacerbation of inflammation and complications caused by them. Thanks to the endoscope, the doctor sees everything that is done inside the sinuses. Based on individual indications for each individual patient, the surgeon may prescribe a combined cleaning, combining the endoscopic method with subsequent therapy. The clinic offers comfortable conditions. Patients will be able to quickly restore their strength after surgery.

Cleaning the sinuses by endoscopic method lasts a different time. The duration of such an operation depends on the complexity of the disease. An experienced specialist will help to make an accurate diagnosis and choose the appropriate treatment. The clinic employs surgeons with extensive clinical practice, there is everything necessary for the diagnosis and performance of such operations.

How is sinus surgery performed?

The patient is placed in a horizontal position, putting a roller under the head. After that, I make incisions in the most suitable places of the nose or sinuses, a probe with a camera is inserted there, which transmits everything seen to the monitor.

In such a situation, patients are guaranteed the exact performance of all the actions of the surgeon. The specialists who carry out surgical cleaning of the sinuses have extensive experience and high medical qualifications. They make an accurate diagnosis, select the best options for the treatment of sinusitis and washing.

The clinic performs safe and painless washing of the maxillary sinuses. The patient does not have to experience pain during the operation. As a rule, after surgery, recovery is fast. Knowing different methods of making an incision, doctors select the most optimal way to flush the sinuses for each person who turns to them. People diagnosed with sinusitis and other diseases of the sinuses and nose can always contact the First Surgery clinic for effective treatment. They offer affordable prices for such medical services and excellent quality of their implementation.