The impact of expiration on particle deposition within the nasal cavity

One of the most important functions of the nose is cleansing the inspired air. The aim of this study was to compare the intranasal deposition of particles during inspiration and expiration, applying different breathing manoeuvres. In nine subjects, the non-deposited particles during inhalation of an aerosol of starch particles were laser-optically detected by placing a suction probe transnasally in the anterior nasal segment. The particle deposition was measured during cyclical nose-in/nose-out (nose-only) and nose-in/mouth-out breathing. The deposited fraction was calculated in percentages. Active anterior rhinomanometry and acoustic rhinometry were performed. The mean deposited fraction in the anterior nasal segment was statistically significantly higher (P < 0.02) during nose-only breathing (46.0%) compared with nose-in/mouth-out breathing (33.0%). Our results suggest that intranasal particle deposition takes place during inspiration as well as during expiration. The period of expiration does not only seem to be important for water and heat recovery, but also for cleansing of the respiratory air.     

Impact of unilateral sinus surgery with resection of the turbinates by means of midfacial degloving on nasal air conditioning

OBJECTIVE/HYPOTHESIS: One of the most important functions of the nose is the climatization of inspired air. The aim of the investigation was to determine the influence of radical sinus surgery with complete resection of the turbinates and the lateral nasal wall by means of midfacial degloving as treatment for inverted papilloma on the nasal humidification and heating of inspired air. STUDY DESIGN: Retrospective study. METHODS: Humidity and temperature were measured in the nasopharynx during normal respiration by means of a miniaturized thermocouple device and a humidity sensor for continuous detection. Eight patients after prior unilateral sinus surgery by means of midfacial degloving for a one-sided inverted papilloma were enrolled into the study. The humidity and temperature data of the surgically treated side were compared to the values of the healthy side that was not surgically treated. Active anterior rhinomanometry and acoustic rhinometry were performed. RESULTS: At the end of inspiration, absolute humidity and temperature values in the nasopharynx were statistically significantly lower on the surgically treated side compared with the side that was not surgically treated. CONCLUSIONS: Radical sinus surgery with resection of the turbinates by means of midfacial degloving seems to disturb the climatization of the inspiratory air in the nasal cavity. Reduced absolute humidity and temperature may contribute to crusting, bleeding, and nasal dryness as frequent complaints of patients after aggressive sinus surgery with resection of the turbinates.     

Numerical simulation of intranasal air flow and temperature after resection of the turbinates

BACKGROUND: Radical surgical resection of the turbinates leads to a reduced intranasal air conditioning. The aim of this study was to determine the effect of turbinate resection on intranasal heating and airflow patterns using a numerical simulation. METHODS: A bilateral model of the human nose with resection of the turbinates on one side based on a CT-scan was reconstructed. A numerical simulation applying the computational fluid dynamics (CFD) solver Fluent 6.1.22 was performed displaying inspiratory intranasal air temperature and airflow patterns. RESULTS: Due to resection of the turbinates the airflow pattern is disturbed resulting in a spacious vortex throughout the entire nasal cavity. Hence, contact between air and surrounding nasal wall is less intense. Consequently, intranasal heating of the inspired air is relevantly reduced. CONCLUSIONS: Surgical resection of the turbinates leads to a disturbed intranasal air conditioning. The presented numerical simulation demonstrates the close relation between airflow patterns and heating.     

Secondary surgical treatment of intranasal deformities of the unilateral cleft palate nose

Intranasal as well as external nasal repair is desirable in the total repair of the unilateral cleft palate nose and in many instances can be achieved concurrently. Carefully performed septal reconstruction will correct the nasal obstruction due to the severe septal deviation to the cleft side and the usual caudal dislocation to the uninvolved side. Since a minimal amount of cartilage is removed, good support is Mayntained for the cartilaginous dorsum. Appropriate management of the turbinates, including extraction, infraction, submucous intramural electrocoagulation, or partial submucous resection will improve the functional result. Because of the better positioning of the septum, some of the alar and columellar abnormalities may be cosmetically improved, and repositioning of the ala or columella will enhance the esthetic appearance.     

Filtration of Particulates in the Human Nose

This report reviews the current theories on the deposition of inhaled particulates in the human nose. The inhalation of particulates represents a challenge to the upper respiratory tract. The concentration of airborne particulates and pollutants varies between occupational and nonoccupational exposure. Regional deposition of potentially hazardous inhaled material determines the local and systemic toxicity. In vitro experiments using casting and molding techniques with water dye models or laser Doppler anemometry indicate that nasal airflow is determined by the size of the nasal valve and the turbinates. The main airstream during inspiration passes through the lower nasal passage. Filtration capacity of the human nose can be expressed mathematically or experimentally. In vivo experiments applying monodisperse or polydisperse aerosols during single or multiple respiratory cycles have shown by using microscopic or laser-optic identification that particles larger than 3µm have a maximum deposition in the anterior part of the nose (nasal valve). Particles smaller than 3 µm and larger than 0.5 µm are filtered by the nasal mucosa and transported by cilia propulsion to the nasopharynx. The filtration for particles smaller than 0.5 µm is low. They seem to pass easily into the lower respiratory tract. This knowledge has an impact on nasal septal surgery and rhinoplasty. By influencing the structure of the nasal valve and the lower turbinates, the filtration capacity of the nose can be significantly decreased.     

Detection of particles within the nasal airways before and after nasal decongestion

Cleansing of the air is one of the most important functions of the nose. The aim of this investigation was to determine the influence of decongestion of the nasal mucosa with xylometazoline on the intranasal particle deposition at different sites of the nasal cavity. During respiration of an aerosol of starch particles, the non-deposited particles in the air were laseroptically detected in 10 healthy volunteers by a transnasally placed suction probe at different locations within the nasal cavity. The anterior nasal segment was the main area of intranasal particle deposition before and after decongestion of the nasal mucosa. Particle deposition after nasal decongestion was not significantly different from the values before application of xylometazoline. Decongestion of the nasal mucosa and increase in nasal cavity diameter seems not to influence particle deposition of inhaled and exhaled air within a short period after onset of the maximal decongestive effect of xylometazoline.     

Particle deposition in the nose related to nasal cavity geometry

A number of studies have been made to characterise the deposition-pattern of inhaled airborne particles in the nose. Common to all results has been considerable differences in deposition fractions between normal human subjects. It was the aim of the current study to improve our understanding of individual differences in nasal deposition of inhaled particles. Depositions were measured in ten adult normal subjects and were related to dimensional measurements by acoustic rhinometry. Five litres of a polydisperse aerosol (MMAD = 0.7 micron, sigma g = 1.7) were inhaled through one nostril only during 5 inspirations with flows of 10, 20, and 30 L/min with decongested mucosa. Increasing flow was found to increase the fraction deposited in the nose, while there was an inverse correlation between nasal deposition fraction and minimum cross-sectional area of the nasal cavity (Amin). Information based on acoustic rhinometry measurements significantly reduced the amount of unexplained variation between subjects in nasal deposition fraction. We conclude that an estimate of maximum linear air velocity, calculated as airflow divided by Amin, was the best single predictor of nasal deposition fraction, which was found to increase with increasing air velocity raised to a power of approximately 4/3.     

Nasal turbinate resection for relief of nasal obstruction

Surgical correction of mechanical nasal airway obstruction is commonly attempted by means of septoplasty or submucous resection. In spite of these procedures, patients continue to present postoperatively with inadequate nasal airflow due to hypertrophied turbinates. Partial resection of turbinate mucosa, submucous turbinate resection, electrocautery and outfracture of turbinates provide additional improvement but are incomplete procedures. Total inferior turbinectomies have been performed on 40 patients over the past 5 years; 29 of these patients have been followed from 2 to 60 months postoperatively by clinical examination and by formal questionnaire. Twenty-five patients described a marked improvement of their nasal breathing, 3 had mild improvement, and 1 had no improvement at all. Only 1 patient, 1 year postoperatively, described excessive dryness, 2 described mild dryness, 3 described excessive secretions and none complained of foul smell or pain postoperatively. All patients had patent airways by clinical examination by at least 2 otolaryngologists. The inferior turbinates play a role in humidification and temperature regulation of inspired air. The removal of them, however, does not seem to be fraught with the morbidity which has heretofore been attributed to this procedure.     

Detection of particles within the nasal airways during respiration

This study introduces a new experimental set-up for particle detection within the nasal airways and describes intranasal deposition of particles at various regions of the nasal cavity and the nasopharynx. During respiration of an aerosol of starch particles the nondeposited particles in the air were detected in 11 volunteers by a transnasally placed suction probe at numerous sites of the nasal cavity and nasopharynx. Another, identical suction probe measured the initial number of inhaled particles at the nostril. The two suction probes were connected to two identical laser particle counters and allowed calculation of particle deposition. Particles 1–3 μm in size were deposited to about 60% within the entire nasal cavity, whereas most of the particles 4–30 μm in size were deposited within the entire nasal cavity. Between 80% and 90% of the particles retained in the nasal cavity were deposited at the anterior nasal segment. Studies on deposition of various drugs within the nasal cavity using this experimental set-up are conceivable. Received: 29 May 2000 / Accepted: 10 August 2000     

Distribution of eosinophils in the nose in patients with perennial rhinitis

The traditional method of classifying perennial rhinitis into eosinophilic and non-eosinophilic is by taking a single nasal smear from one nostril. In the light of personal experience it was felt that this method of sampling may be inadequate. The present study included 20 patients with perennial rhinitis undergoing nasal surgery. Serum total IgE levels were taken and those above 40 IU/ml had allergen specific IgE measured. Nasal smears and biopsies were taken from 5 sites on each side of the nose: middle and inferior turbinates and post nasal space. The smears significantly correlated with the biopsies (r_s= 0.446, P < 0.001). The distribution of eosinophils between and within nasal cavities was found to differ. Representative sampling of the nose is important for accurate eosinophil expression. The definition of an eosinophil rich and poor nose requires greater clarification as it has great clinical relevance regarding management.     

Distribution of eosinophils in the nose in patients with perennial rhinitis.

The traditional method of classifying perennial rhinitis into eosinophilic and non-eosinophilic is by taking a single nasal smear from one nostril. In the light of personal experience it was felt that this method of sampling may be inadequate. The present study included 20 patients with perennial rhinitis undergoing nasal surgery. Serum total IgE levels were taken and those above 40 IU/ml had allergen specific IgE measured. Nasal smears and biopsies were taken from 5 sites on each side of the nose; middle and inferior turbinates and post nasal space. The smears significantly correlated with the biopsies (rs = 0.446, P < 0.001). The distribution of eosinophils between and within nasal cavities was found to differ. Representative sampling of the nose is important for accurate eosinophil expression. The definition of an eosinophil rich and poor nose requires greater clarification as it has great clinical relevance regarding management.     

Transnasal endoscopic surgery of the pituitary: modifications and results over 10 years

OBJECTIVE: A 10-year retrospective review of three endoscopic approaches used by the authors for pituitary gland surgery is presented. We review our results and complications and outline the advantages and disadvantages of each. The variations in nasal anatomy that factor in the endoscopic approach are tabulated and discussed. METHODS: A chart review and examination of computed tomography and magnetic resonance imaging scans of patients who have had endoscopic pituitary surgery by the authors was performed. We gathered specific details of the operative approach, nasal-sinus anatomy, tumor location, required ancillary nasal procedures, and postoperative complications. RESULTS: Ninety patients had endoscopic pituitary surgery. Operative reports and review of radiographic studies were possible for 75 patients. The surgical approach progressed over 10 years from endoscopic transseptal (42) to bilateral transostial (13) to unilateral transostial (20). Adequate exposure for the degree of resection was achieved in all patients. Complications included hemorrhage requiring return to the operating room (1), transient visual field loss (2), and transient diabetes insipidus (7). Four patients subsequently had craniotomy to resect suprasellar tumor extension. The average follow-up was 6 years. One patient required revision endoscopic resection 3 years later for tumor recurrence. Anatomic findings included nasal septal deflections in 36 (48%) of the patients, abnormalities of the turbinates in 42 (56%), and variances of the sphenoid sinus septum in 59 (79%) of the patients. In the unilateral transostial approach, the operative side was often determined by anatomic factors. CONCLUSION: The authors have exclusively used endoscopic surgery of pituitary gland tumors for over 10 years. Modifications to the approach have occurred as a result of increased surgeon experience and improved technology. The unilateral transostial approach is safe, effective, and recommended.     

Numerical simulation of intranasal airflow after radical sinus surgery

PURPOSE: Radical sinus surgery disturbs intranasal humidification and heating of inspired air, resulting in reduced air conditioning mainly caused by a disturbed airflow. Therefore, the aim of this study was to simulate the intranasal airflow after radical sinus surgery during inspiration by means of numerical simulation. MATERIAL AND METHODS: A bilateral model of the human nose with maxillectomy, ethmoidectomy, and resection of the lateral nasal wall and the turbinates on one side based on a multislice computed tomographic scan was reconstructed. An unsteady numerical simulation displaying the intranasal airflow patterns applying the computational fluid dynamics solver Fluent 6.1.22 was performed. RESULTS: Spacious vortices throughout the entire nasal cavity and the paranasal sinuses caused by the radical resections occurred, causing a less-intense contact between air and the surrounding nasal wall. An enlargement of the nasal cavity volume and a reduction of the nasal surface area in ratio to the nasal cavity volume could be observed. CONCLUSIONS: Aggressive sinus surgery leads to disturbed intranasal air conditioning caused by disturbed intranasal airflow patterns and a reduction of the surface area in relation to the nasal volume. The presented numerical simulation demonstrates the close relation between air conditioning and intranasal airflow. It can be helpful to understand and interpret in vivo measured data of intranasal temperature and humidity.     

A dynamic and direct visualization model for the study of nasal airflow.

OBJECTIVE: To evaluate nasal airflow characteristics during physiologic breathing in normal and pathologic conditions. DESIGN: The choana of an anatomical human model was connected to a pump that simulated physiological pressure changes in the upper airway system. Normal ambient air was used as medium. The airstream was marked with aerosolized water particles, and was observed through an exact but translucent replica of the original nasal septum. RESULTS: In physiologic conditions the airflow is mixed. Turbulence is clearly visible even with low flow velocities. There is less turbulence with lower flow rates. The nasal airflow follows a triphasic pattern of acceleration, near-steady state, and deceleration. Turbulence is prominent in the first and third phases. The main flow stream passes through the middle meatus at all rates. Hypertrophic mucosal membranes and turbinates increase the proportion of air passing the middle meatus. With decongested turbinates, flow distribution is more even. After turbinectomy there is a significant amount of airflow passing along the floor of the nose. The olfactory region is aerated only toward the end of inspiration and during the entire expiration phase. CONCLUSIONS: This model allows the investigation of airflow distribution and turbulence under physiologic conditions and the examination of the influence of pathologic conditions on these parameters. Overzealous trimming of turbinates results in an unphysiologic distribution of airflow.     

Septal cartilage graft for nasal valve incompetence associated with deviated septum

BACKGROUND: The nasal valve is one of the major factors contributing to nasal airflow obstruction. Physiologically, the nasal valve offers the greatest resistance to nasal airflow and generally functions as an inflow device controlling nasal airflow and resistance. Many patients who have complaints of breathing impairment are affected by alterations of the nasal septum, the turbinates, the columellar base, the vestibule floor, or the lateral wall of the nose but may have associated incompetence of the nasal valve, which is too often undervalued by nasal surgeons. The aim of this study was to propose a relatively easy surgical technique to correct most nasal valve impairments associated with nasal septum deviation whether or not there also is inferior turbinate hypertrophy. METHODS: Between May 2004 and September 2006, 68 patients (26 women and 42 men; mean age, 37 years; range, 16-71 years) underwent primary or secondary functional nasal surgery, because of a nasal respiratory obstruction caused by nasal septal deviation eventually associated with inferior turbinates hypertrophy, and also demonstrated nasal valvular incompetence. A septal cartilage graft was used to correct the valvular incompetence. RESULTS: On postoperative visits almost all of the patients (with one exception) showed a remarkable improvement in the stiffening of the valvular region and had only minimal depression of the nostril during deep inspiration. CONCLUSION: This study indicated that septal grafts were useful in the surgical management of nasal respiratory impairment because of nasal valve incompetence, where there had been flaccid mobile collapse of the ala of the nose associated with septal alterations.     

Cryosurgery of the inferior nasal turbinates

Forty-seven patients with irreversible nasal obstruction due to inferior turbinate hypertrophy were treated by cryosurgery, the short and medium term results having been clinically evaluated. Permanent good results in nasal breathing were achieved in 83% of the patients. Failures are mostly related to turbinates hypertrophy due to nasal allergy. The combination of cryosurgery and nasal septoplasty, in cases of hypertrophy associated with deformities of nasal septum, gives an excellent result. Cryosurgery of hypertrophic nasal turbinates is a simple, safe, and reliable procedure to improve nasal breathing in cases of nasal turbinate hypertrophy.     

Nasal sequels of unilateral clefts: analysis and management

Usually, the nasal sequels of unilateral cleft patient are just considered as an esthetic problem to be addressed after the growth spurt of adolescence. This very narrow vision has led the cleft lip and palate treatment to a deadend. Actually, nasal sequels are the worst in terms of consequence on facial growth. 75% of complete unilateral cleft children are more oral than nasal breathers. Today, we know about the bad consequences of oral breathing on facial growth. It is not surprising to observe a high rate of small maxilla with cleft maxilla scars. In the fetus, the unilateral cleft nose deformities are well explained by the rupture of the facial envelope and the ventilatory dynamics of the amniotic fluid. Every step of the primary treatment threatens the nasal air way patency, whether when repairing lip and nose, suturing the hard palate that is the floor of the nose, or closing the alveolar cleft which controls the width of the piriform aperture. The functional and esthetic nasal sequels reflect the initial deformity, but are also the surgeon's skill and protocol choice. Before undertaking treatment, we must analyze the deformity at every level. Usually, the best option is to reopen the cleft completely to perform a combined revision of the lip, nose, and alveolar cleft after an adequate anterior maxillary expansion. If nasal breathing is necessary for an adequate facial growth, 25 years of experience showed us that it was very difficult to erase the cortical imprint of an early oral breathing pattern. So it is essential to establish a normal nasal breathing mode at the initial surgery. When the initial surgery is efficient and/or the secondary repair is successful, the final esthetic rhinoplasty, when indicated, is just performed for the sake of harmonization, with a classic internal approach and a few refinements.     

First results of the wave-guide in CO2-laser surgical reduction of the hyperplastic nasal turbinates

BACKGROUND: The CO2-laser-surgical reduction of the hyperplastic nasal turbinates represents a standard procedure in ENT-Surgery. In the presented paper, the authors introduce a new technique for the treatment of hyperplastic turbinates. METHODS: The laser beam is transmitted through a 90 degrees handpiece to the mobile "infra-guide" wave guide, which contains a 1 mm ceramic tube. By application of mirrow pieces with different angles, laser surgical reduction of those parts of the nasal turbinates is possible, which normally can not be reached by conventional, tangentially to the mucosa directed laser beams. The direction of the laser beam is controlled either optically, as in endonasal sinus surgery, or monitored through a camera. A total of 36 patients (22 women, 14 men, mean age 32.7 years) with nasal turbinate hyperplasia and either impaired nasal breathing and/or retronasal drip were treated with the new method. RESULTS: The laser wave guide represents a minimally invasive and basically complication-free method feasable on an outpatient basis. As a particular advantage, laser surgical reduction of the posterior parts of the inferior and also the middle turbinate is possible. The majority of the patients relates of an improvement of the preoperative symptoms (regarding reduction of impaired nasal breathing: 61.3 %, regarding reduction of post nasal drip 87.1 %). CONCLUSION: The laser wave-guide represents a basically complication-free, minimally invasive supplement to the different treatment modalities of the hyperplastic nasal turbinates.     

Nasal resistance during wakefulness and sleep in normal man

Previously, we reported an increase in supralaryngeal resistance during sleep in normal man. Since nasal resistance is known to fluctuate over a wide range of circumstances, we hypothesized that the increase in supralaryngeal resistance observed was due to an increase in nasal resistance. Therefore, the purpose of this investigation was to examine changes in total and unilateral nasal resistance in five normal, adult males during wakefulness, Stage 2 (non-REM) sleep and REM sleep. Transnasal pressure and flow were measured for each side of the nose. Resistance was calculated from the slope of the linear portion of the transnasal pressure-flow relationship. During wakefulness and sleep, resistance was substantially higher on one side of the nose or unilateral total occlusion was present. This high resistance fluctuated from side to side during sleep. The transition of high resistance from side-to-side occurred rapidly. On turning to either side, the side of the nose with the high resistance was not necessarily the gravitationally-dependent side. Total nasal resistance did not change significantly during sleep. We concluded that 1) resistance on one side of the nose is usually considerably higher than the other side, 2) this high resistance side alternates during sleep as well as wakefulness, 3) since this alteration occurs rapidly and is not dependent on gravity, reflexes are likely involved and 4) changes in total nasal resistance were not responsible for the increased supralaryngeal resistance we have observed during sleep.     

First findings concerning airflow in noses with septal deviation and compensatory turbinate hypertrophy--a model study

BACKGROUND: The nasal septal deviation is a common cause of nasal obstruction. On the other hand, many septal deviations are asymptomatic. It seems a physiological adaptation occurs on both sides. Septal deviation leads to internal nasal asymmetry, which in turn causes compensatory change in turbinate morphology (e.g. turbinate hypertrophy respectively hypotrophy). This mechanism is investigated with the help of fluid dynamic experiments and functional rhinologic diagnostics. METHODS: Functional models of the nose (modified Mink's boxes) were used and assessment was made by acoustic rhinometry and rhinoresistometry, followed by flow dynamic investigations. Septal deviations of varying position, together with turbinates of differing grades of hypertrophy, were simulated and assessed. RESULTS AND CONCLUSIONS: We observed in models of septal deviation an increase in flow resistance on the ipsilateral side as a result of friction of flow particles in the narrowing. Furthermore, on the opposite side of the deviation, the enlargement of the stream channel did not generally lead to a reduction in flow resistance, but rather to a 'dead space', where only a slow-circling eddy was observed. This eddy causes an increase in turbulence. In vivo turbinate hypertrophy occurs to fill this dead space, thereby reducing turbulent flow without a significant increase in resistance. In cases of moderate septal deviation, compensatory mechanisms of the turbinates can lead to a normalization of nasal airflow and surgical therapy would not be indicated. Deviations in the anterior part of the septum seem to be more symptomatic, because the mechanism is missing and due to the physiological narrowing of the nasal isthmus. To differ between physiologic and pathologic deviation, functional diagnostics are needed.