First – What Does the Nose Do?
For those who do not know, the nasal septum is the wall that divides the right and left nasal passages. The lower nasal turbinates are structures that protrude from the right and left side walls of the nasal passages. When you breathe, each passage is separate from the other by the nasal septum. Air travels through each side, flowing over the lower turbinates and “conditioned” in such a way that the air that reaches the back of your nose has been properly filtered, warmed and humidified to be acceptable for flow into the lungs.
The nasal passages are often a source of obstruction, either due to past trauma, natural shape of the inside of the nose, or due to congestive changes (with large nasal turbinates) that ultimately require possible septal surgery and / or turbinate reductions.
Both sides of the septum and the surface of the lower turbinates are covered in nasal mucous membrane, which includes two important type of cells. The first type is the mucous cell, which creates and secretes mucous into the nose. All of the mucous cells together in the nose form a patchwork of cells on a surface, each creating mucous, so that it ends up being like a tiny lake of mucous on the surface. That mucous sits on the surface of the mucous membrane, trapping dust, pollens, viruses and bacteria from the airflow.
The other type of cell among those mucous producing cells are called ciliated cells. These cells have finger like projections sticking out of the top that move like a wagging finger in a particular direction. That means they do not move randomly, they have a distinct direction in which they wave. Usually, all those individual cilia wave in such a way that points to the back of the nose. The reason we have those ciliated cells is to establish a current of flow of that mucous from where it gets secreted on the nasal membrane towards the back of the nose. That way, as particles are getting caught in the mucous (like leaves on a flowing river), they are slowly being herded towards the back of the nose (like towards the water fall). That mucous that flows over the edge is… yes, I am afraid to have to gross you out… swallowed. Think of it like sending that material into the incinerator of your acid-filled stomach. You will also recycle the proteins in your mucous.
What Happens After Nasal Surgery?
The cells in your nose work like a community of individuals. The various mucous producing cells produce their mucous, much like a group of bakers making bread and putting it out on the conveyor belt. The ciliated cells move in a particular direction, like a conveyor belt moving in a direction, moving that mucous through the nose towards the back, allowing it to trap particles that you happen to breathe in. That movement is part of the reason we (usually) do not get sick very often despite the fact we breathe in a LOT of viruses all the time. It takes time for a virus to land in the mucous, “sink” to the bottom and reach the mucous membrane surface, attach to it (in a flowing current of mucous) and finally invade the membrane cell. Once it has invaded the cell membrane, then we have to rely on our immunity to deal with it.
After surgery, two things happen that cause trouble. First, we have just injured the nasal membrane. It will react by by producing a lot more mucous. In nature, our original blueprints did not account for “surgery”. It accounted mainly for the event that could conceivably kill us: the virus. It produces a lot more mucous to try to “drown” the problem. This is all well and good, except for the second problem. The injury we create in performing surgery also tends to stun those ciliated cells, so the conveyor belt stops moving in most areas. That means we are creating more mucous, and there is no movement. That mucous starts to build up, and because there is air flow, particles getting caught in it (like more and more leaves landing now in a still lake rather than a flowing river), that stagnant pool starts to dry up in places (creating crusts), and some of the viruses we are breathing in can sink to the bottom and invade our vulnerable cells.
It takes a good 4-6 weeks for the nasal membranes to start working properly again. In the meantime, surgeons usually advise patients to rinse their noses with a saline rinse on a regular basis. You have to manually help flush that accumulating mucous out of the nasal passages. Using saline this way helps replace the function of those stunned ciliated cells until they can take over again. Here is a videoshowing how to use a nasal rinse.
You will reduce the crusting and infections that can take place after surgery, and end up with a much better breathing result afterwards.