空鼻症候群

手术治疗

Surgical treatment involves narrowing back the over enlarged nasal cavity—either by bulking up the partially resected turbinates with biological implant material (in cases where at least 50% of the inferior turbinate remain from anterior to posterior) or by creating neo-turbinates through submucosal implantation between the submucosa and bone in key locations in the nasal cavity. Of course, in some cases a combined approach is the best choice. The main difficulty with implant surgery is to achieve a long lasting bulk that will not get absorbed over time. Sometimes a procedure has to be repeated several times to get a sustainable result. The most physiological location for an implant is the lateral wall of the nasal cavity, where the inferior turbinate used to project from. An easier location to implant is the septum, but it is less favorable as it is not the natural location of the turbinates and may over obstruct the airflow.

The underlying rationale of surgery is to restore the natural inner nasal geometrical contours of the nasal passages of air (the inferior, middle, and superior meatuses), as much as possible, to mitigate the airflow just enough to restore normal rates of inner nasal humidity and temperature that will allow the mucosa to recuperate and sense the airflow well enough. It is paramount to do so while trying to restore the normal aerodynamics of the airflow in the nose, otherwise nasal obstruction will occur.

Pre-surgical planning has a tremendous impact on the success of the procedure. The surgeon is advised to perform a cotton test prior to the implantation: the surgeon places saline soaked chunks of cotton wool at the pre-planned site of implantation to simulate the implant. By doing so, he restricts and normalizes the nasal airflow patterns. This restores nasal aerodynamics. By trying different locations in accordance to the patient's feedbacks regarding the quality of his breathing and other ENS symptoms, it is possible to pinpoint the exact placement for the implants and their estimated shape and size.

Turbinate tissue is unique and there are no potential donor sites in the body from which to harvest similar tissue. However, in the nose, form equals function. It is therefore possible to restore some function by restoring the natural contours and proportions of the nasal passages: It is possible to create an artificial look-alike structure of a turbinate in the nasal cavities, and thus to regain some of the nose's capabilities to adequately resist, streamline, heat, humidify, filter, and sense the airflow.

• A video demonstrating lateral wall implantation to create a bulk of tissue that will simulate the shape and function of the resected inferior turbinate. （页面存档备份，存于互联网档案馆）

Implant materials

Before and after implantation of the lateral wall with Alloderm to simulate the function of the missing inferior turbinate.

The bulking up of the sub-mucosa and mucosa to create a neo-turbinate structure can be achieved through implanting some supporting material between the bone/cartilage and also into the submucosal layer. Many materials have been tried over the past 100 years. In most cases this operation was used to restore heat and humidity to atrophic noses.

Generally speaking, the implant materials can be divided into 3 groups:

• autografts: bone, cartilage, fat, etc. from one site to another in the same patient. The problems here are relative shortage of tissue, and long term studies have shown high absorption rates in the nose. A Chinese study reported long-term success using iliac bone autografts.
• foreign materials: such as fibrin glue, Teflon, Gore-Tex, and plastipore, which solve the problem of shortage of autografts, are easy to shape and do not tend to get absorbed. However they have a high extrusion rate, and sometimes cause infection. A case study of good retention of hydroxyapatite cement in one patient has been reported in 2000, but the follow-up was only 1 year long.
• allografts: In the last two decades scientists have been able to harvest and remove away genetic markers of some basic human tissues (like skin dermis) from donors, and thus supplying a human natural implant material which does not stimulate the immune system to reject it. A good example for such material is acellular dermis (brand named "Alloderm"). It does not get rejected and in most areas retains most of its volume over long periods.

The ideal implant material, other than real original turbinate tissue should be something with low extrusion and rejection rates, minimal infection risk, and—very importantly—that will provide a strong and endurable enough structure and at the same time allow good permeability for blood vessel incorporation, which seems to be the key against long term absorption.