Sinus Function Research Articles

Miniseminar: Controversies in endoscopic sinus and nasal surgery: How much is enough? Update 2004

Since the late 1800s surgeons have been treating chronic sinus disease with surgical drainage procedures. For over a century, techniques have been refined based on current theory of sinus function, an understanding of anatomy, and the availability of new technology. We currently benefit from Messerklinger’s work on functional endoscopic sinus surgery and the advent of modern endoscopes, as well as computer imaging and powered dissection. In this era of evidence-based medicine, otolaryngologists are faced with defining the need for surgery and in proving the success of our outcomes alleviating our patients’ ills. As we try to better define our methods, we also find controversy in the extent of surgery that is necessary. Is there a need to widely open the maxillary sinus or its ostium or is removal of the uncinate process sufficient? How much dissection is necessary at the frontal recess and frontal sinus? While some of these questions must be answered based on the merits of the individual case, there are differences of opinion as to the basic decision on what tissue should be removed and what is inviolate. We present a forum where experts in the field will review opposing points of view on the extent of dissection necessary in FESS, correlating their opinion with available literature and outcome data.

Gene dose-dependent atrial arrhythmias, heart block, and brady-cardiomyopathy in mice overexpressing A3 adenosine receptors

Objective: An increased expression of adenosine receptors is a promising target for gene therapy aimed at protecting the myocardium against ischemic damage, but may alter cardiac electrophysiology. We therefore studied the effects of heart-directed overexpression of A3 adenosine receptors (A3ARs) at different gene doses on sinus and atrio-ventricular (AV) nodal function in mice. Methods and results: Mice with heart-specific overexpression of A3AR at high (A3high) or low (A3low) levels and their wild-type littermates were studied. Telemetric electrocardiogram (ECG) recordings in adult freely moving A3high mice showed profound sinus bradycardia resulting in either ventricular escape rhythms or an incessant bradycardia–tachycardia syndrome (minimal heart rate A3high 217±25*; WT 406±21 beats/min, all values as mean±S.E.M., n=7 per genotype, *p<0.05). Exercise attenuated bradycardia in A3high mice (maximal heart rate A3high 650±13*; WT 796±13 beats/min) and first-degree AV nodal block was present (PQ interval A3high 36±4*; WT 23±5 ms). Isolated hearts showed complete heart block (10/17 A3high* vs. 1/17 WT). Atrial bradycardia and AV block were already present 3 weeks after birth. Doppler echocardiography revealed atrial dysfunction and progressive atrial enlargement that was moderate at 3 and 8 weeks, and progressed at 12 and 21 weeks of age (all p<0.05 vs. WT). Atrial contractility and sarcoendoplasmic Ca2+ ATPase (SERCA) 2a protein expression were reduced in isolated left A3high atria at the age of 14 weeks. Fibrosis was present in left A3high atria at 14 weeks, but not at 5 weeks of age. A3low mice had first-degree AV block without arrhythmias or structural changes. Conclusions: Heart-directed overexpression of A3AR resulted in gene dose-dependent AV block and pronounced sinus nodal dysfunction in vivo. Profound bradycardia heralded atrial and ventricular dilatation, dysfunction, and fibrosis. In contrast to A1 adenosine receptors (A1AR), the effects of A3AR overexpression were attenuated during exercise. This may have implications for the physiology of sinus nodal regulation and for therapeutic attempts to increase the expression of adenosine receptors.

Gene dose-dependent atrial arrhythmias, heart block, and brady-cardiomyopathy in mice overexpressing A(3) adenosine receptors.

An increased expression of adenosine receptors is a promising target for gene therapy aimed at protecting the myocardium against ischemic damage, but may alter cardiac electrophysiology. We therefore studied the effects of heart-directed overexpression of A(3) adenosine receptors (A(3)ARs) at different gene doses on sinus and atrio-ventricular (AV) nodal function in mice. Mice with heart-specific overexpression of A(3)AR at high (A(3)(high)) or low (A(3)(low)) levels and their wild-type littermates were studied. Telemetric electrocardiogram (ECG) recordings in adult freely moving A(3)(high) mice showed profound sinus bradycardia resulting in either ventricular escape rhythms or an incessant bradycardia-tachycardia syndrome (minimal heart rate A(3)(high) 217+/-25*; WT 406+/-21 beats/min, all values as mean+/-S.E.M., n=7 per genotype, *p<0.05). Exercise attenuated bradycardia in A(3)(high) mice (maximal heart rate A(3)(high) 650+/-13*; WT 796+/-13 beats/min) and first-degree AV nodal block was present (PQ interval A(3)(high) 36+/-4*; WT 23+/-5 ms). Isolated hearts showed complete heart block (10/17 A(3)(high)* vs. 1/17 WT). Atrial bradycardia and AV block were already present 3 weeks after birth. Doppler echocardiography revealed atrial dysfunction and progressive atrial enlargement that was moderate at 3 and 8 weeks, and progressed at 12 and 21 weeks of age (all p<0.05 vs. WT). Atrial contractility and sarcoendoplasmic Ca(2+) ATPase (SERCA) 2a protein expression were reduced in isolated left A(3)(high) atria at the age of 14 weeks. Fibrosis was present in left A(3)(high) atria at 14 weeks, but not at 5 weeks of age. A(3)(low) mice had first-degree AV block without arrhythmias or structural changes. Heart-directed overexpression of A(3)AR resulted in gene dose-dependent AV block and pronounced sinus nodal dysfunction in vivo. Profound bradycardia heralded atrial and ventricular dilatation, dysfunction, and fibrosis. In contrast to A(1) adenosine receptors (A(1)AR), the effects of A(3)AR overexpression were attenuated during exercise. This may have implications for the physiology of sinus nodal regulation and for therapeutic attempts to increase the expression of adenosine receptors.

A simplified method to determine acetabular cup anteversion from plain radiographs

Plain radiographs are the most important diagnostic means for determining the indication and following up on total hip arthroplasty. The acetabular cup position can be easily determined by applying trigonometric functions. This report presents an even simpler method. The short axis of the projected ellipse is measured and related to the total cross-section of the projected cup along the short axis. This relationship correlates with acetabular cup anteversion angles and represents an inverse sinus function. A close linear correlation is seen within the most common interval from 10° to 30°. Anteversion is between 23° to 24° when the ellipse bisects the total acetabular cross-section. This means that simply measuring the length of the short ellipse axis and the total length of the projected cross-section along the short axis provides the radiographic acetabular anteversion. Nonorthogonal projected radiographs should be corrected first.

The influence of the blocking plate diameter on the gas flux distribution in the calibration chamber

This paper is concerned with the influence of the diameter of the blocking plate on the gas flux density distribution in a typical calibration chamber. It was found that, at small values of the blocking plate diameter, the shape of the gas flux density function is similar to the sinus function, with zero deviation from the mean value of the gas flux density at mid-height of the chamber. As the blocking plate diameter increases a discontinuity appears at the edge of the “shadow zone”. Until the discontinuity occurs on the side wall, the difference between the maximum and minimum relative gas flux densities is about 3×10 −4, then it grows to 3.7×10 −3 when the relative blocking plate diameter increases to 0.83 of the chamber diameter. If we confine our attention to the region between 0.33 and 0.67 of the whole chamber height, which is reasonable in practical terms, the maximum difference decreases to 6×10 −4. Even in this case, this difference is twice as great as that in the case of the chamber without or with the smallest reasonable blocking plate.

P-500 Comparative efficacy of bolus intravenous ATP and adenosine on sinus and AV nodal function

P-500 Comparative efficacy of bolus intravenous ATP and adenosine on sinus and AV nodal function

P-500 Comparative efficacy of bolus intravenous ATP and adenosine on sinus and AV nodal function

P-500 Comparative efficacy of bolus intravenous ATP and adenosine on sinus and AV nodal function

Staphylococcus aureus bacteremia after median sternotomy: clinical utility of blood culture results in the identification of postoperative mediastinitis

The hemodynamic and electrophysiologic effects of rilmenidine were examined after single oral administration to hypertensive patients.In 8 untreated hypertensive patients, cardiac output, pulmonary pressure and blood pressure were measured before and for 10 hours after the administration of 25 μg/kg of rilmenidine (1.3 to 2.4 mg, mean 1.88). In addition, electrophysiologic investigations were performed before and 2 hours after administration.Hemodynamics were repeated in 8 other hypertensive patients receiving 50 μg/kg rilmenidine (3.0 to 4.8 mg, mean 3.85 mg).The electrophysiologic study was repeated in 8 other hypertensive patients receiving 50 μg/kg of rilmenidine (3.2 to 4.4 mg, mean 3.90).In contrast to the results obtained at the dose of 50 μg/kg, there was no significant variation in pulmonary arterial pressure, cardiac index or stroke index after administration of 25 μg/kg. No significant variation was observed in heart rate, sinus function, conduction parameters or atrial, nodal and ventricular refractory periods after adminstration of 25 and 50 μg/kg.Rilmenidine, after single oral administration at the 25 μg/kg dose, led to a significant reduction in blood pressure and peripheral resistance without any significant change in cardiac output; the 25-and 50-μg/kg doses led to no alteration in heart rate and cardiac electrophysiology.

1P-0030 Evaluation of coronary sinus function in patients with three-vessel disease

1P-0030 Evaluation of coronary sinus function in patients with three-vessel disease

Localization and Quantitation of Eotaxin mRNA in Human Nasal Polyps

Nasal Polyps (NPs) are the most common mass lesions found in the nose. NPs cause airway obstruction, prevent normal sinus function, and can lead to infection of the eye, facial bones and central nervous system. The predominant cell type inhabiting NPs is the eosinophil, and the chemokine eotaxin is believed to play an important role in NP eosinophilia. The objective of this study was to localize and quantitate expression of eotaxin mRNA in human NPs. Total RNA was isolated from NPs that were collected from 5 patients who had undergone polypectomy. Portions of these polyps were also fixed in formalin, embedded in paraffin, and sectioned onto slides for use in in situ hybridization. Total RNA from one patient was used in a reverse transcriptase polymerase chain reaction using eotaxin specific primers to generate a human eotaxin cDNA. The eotaxin cDNA was cloned and used to generate probes for Northern blot analyses and for use in in situ hybridization (ISH). Eotaxin mRNA was detected by Northern analyses in all patient samples, though the relative expression level in each patient varied. ISH localized the expression of eotaxin mRNA specifically in eosinophils in 2 of the 3 patients in the study for whom the embedded polyp tissue appeared sufficiently well preserved for mRNA localization. Our findings suggest that eosinophilia in NPs is likely a self‐amplification process whereby increasing numbers of eosinophils are recruited to enter the polyp as a result of production of eotaxin by eosinophils already within the polyp.

Sinusitis: Postoperative changes and surgical complications

Functional endoscopic sinus surgery (FESS) is the standard of care for the surgical management of sinonasal inflammatory disease. This group of procedures focuses on the sinus outflow tract, and is designed to improve sinus function by restoring sinonasal physiology. Use of the monocular endoscope is associated with a range of unique surgical complications that often require cross-sectional imaging. Many patients considering sinus surgery today have had surgical procedures in the past that were directed at removing diseased mucosa, rather than improving sinus drainage, and have a different appearance on CT. This report addresses the spectrum of surgical changes found on postoperative imaging of the paranasal sinuses, and the surgical complications that may occur during endoscopic sinus surgery.

Genetic programming: principles and applications

Genetic algorithms (GA) has given rise to two new fields of research where (global) optimisation is of crucial importance: ‘ genetic based machine learning’ (GBML) and ‘ genetic programming’ (GP). An introduction by the authors to GA and GBML was given in two previous papers (Eng. Appl. Artif. Intell. 9(6) (1996) 681; Eng. Appl. Artif. Intell. 13(4) (2000) 381). In this paper, the last domain (GP) will be introduced, thereby making up a trilogy which gives a general overview of the whole field. In this third part, an overview will be given of the basic concepts of GP as defined by Koza. A first (educational) example of GP is given by solving a simple symbolic regression of a sinus function. Finally, a more complex application is presented in which GP is used to construct the mathematical equations for an industrial process. To this end, the case study ‘fibre-to-yarn production process’ is introduced. The goal of this study is the automatic development of mathematical equations for the prediction of spinnability and (possible) resulting yarn strength. It is shown that (relatively) simple equations can be obtained which describe accurately 90% of the fibre-to-yarn database.

Sinusitis-induced Enophthalmos: The Silent Sinus Syndrome

Enophthalmos caused by inadequate maxillary sinus function was first reported in 1964. Since this initial report, scattered case reports and, more recently, reviews have appeared in the literature detailing the pathophysiology, clinical findings, and management of this process. We present a classic case of the asymptomatic development of enophthalmos caused by maxillary sinus hypoventilation: the silent sinus syndrome. In addition, this case included findings in the ethmoid sinuses that suggested their contribution to this disorder, which by our review of the literature has not been well described.

Heart transplantation: Influence of the surgical technique on sinus function

This study analyzes the influence of the surgical technique on the development of sinus dysfunction. Cycle length, corrected sinus node recovery time, and sinoatrial conduction time were determined in 4 groups of dogs under the following conditions: group 1, controls; group 2, subjected to heterotopic heart transplantation with conservation of atrial anatomy; group 3, subjected to orthotopic heart transplantation by using a standard technique; and group 4, treated as in group3, but with an ischemic time of 24 hours. The cycle length was prolonged in all the treated groups when compared with the controls ( P < .01), an effect attributed to the disconnection of the autonomic nervous system during the transplantation procedure. The corrected sinus node recovery time and sinoatrial conduction time were significantly longer in all the animals in groups 3 and 4 when compared with those of groups 1 and 2 ( P < .01); however, there were no significant differences between groups 3 and 4 or between groups 1 and 2. These results suggest that the atrial anatomy play a more relevant role than the ischemic time in the origin of sinus dysfunction occurring after orthotopic heart transplantation.

Endoscopic sinus surgery in flowing water

A balloon has been developed that completely fills the choana, preventing water from leaking into the pharynx even when the water is entering into the nasal cavity at a rate of 1000 ml per minute. The balloon enables endoscopic sinus surgery (ESS) to be safely performed in "flowing water". This surgical technique is similar to that used in transurethral resections of the prostate because the tip of the endoscope is kept clean, and blood, debris and resected tissues are continuously removed by the water flow. In addition, the water pressure helps to suppress bleeding. This technique enables ESS to be performed with greater ease and efficiency. We have performed ESS in flowing water on 38 patients with chronic sinusitis under local anaesthesia. No complications, such as water leakage into the pharynx, were encountered, and only a few patients felt discomfort from the insertion of the balloon. Even if the balloon had burst, an emergency could have been easily prevented by withdrawing the endoscope from the nasal cavity and stopping the flow of water. Ultrasonography (USG) was used to examine the water-filled nasal cavity during surgery (SSD-2000 and Micro Tip Radial (ASU-101); Aloka, Ltd., Japan). Using USG, the middle turbinate, the inferior turbinate and the nasal septum could be visualized in a single coronal image. When the sensor was in the posterior ethmoid sinus, the orbit and its optic nerve could also be visualized. Since this surgery is performed under local anesthesia, eye movements can rapidly alter the position of the optic nerve. Thus, visualization of the optic nerve's exact position is extremely important. Unfortunately, USG is not very useful for localizing structures and guiding the surgeon to distant tumors or cysts located behind thick bones, since ultrasound can not penetrate hard masses or bones. In this situation, navigation systems are more reliable than USG. Nevertheless, USG is often useful for depicting surgical sites, especially during a crisis, if the medial wall of the orbit is thin or if the skull base has been broken, exposing the dura. USG can also provide early warning of an impending complication. USG also has several practical advantages over navigation systems: the cost of USG is much lower, preparation for surgery is unnecessary, visual information can be obtained in real time, and measurement accuracy (estimated to be about 2 mm for navigation systems) is not a consideration. Thus, USG can be easily used to avoid complications in most surgeries for chronic sinusitis. Flowing water also allows the nasal eavity to be completely washed and sterilized at the end of the surgery. This not only prevents post-operative infection, but enables sinus function to be more quickly recovered. In addition, the pressure from the balloon also prevents post-operative nasal hemorrhaging. This allows patients to be safely discharged from the hospital at an earlier time. The balloon can also be used for non-surgical purposes. For example, emergent epistaxis can be easily stopped by the insertion of this balloon, even if the doctor is not an otorhinolaryngologist. In addition, the balloon's soft pressure allows it to be left in the nose for long periods without any complications. We conclude that this simple balloon, which we have named the "Noda Balloon", is extremely useful for nasal treatments.

Nasal obstruction: an alternative to ostiomeatal complex dysfunction in sinus disease.

Ostial patency is thought to be essential to the function of the maxillary sinus. Ostiomeatal complex dysfunction has been implicated as a major factor in the pathogenesis of sinus disease. However, recent work in our laboratory has indicated that other factors may also contribute to this process. The objective of this study was to determine the effect of nasal obstruction in maxillary sinus gas composition, independent of its effect on ostial ventilation. Prospective controlled animal study. Independent models of nasal obstruction and ostial occlusion in contralateral sinuses were established. Ipsilateral models of nasal obstruction and ostial occlusion were also created. Gas samples from each of the manipulated sinuses were analyzed on a gas chromatogram and compared. Results revealed a dramatic and highly significant increase in antral carbon dioxide (CO2) concentrations in the sinuses ipsilateral to either an occluded ostium or an obstructed nostril, compared with the controls. These effects on CO2 concentrations were additive when ipsilateral nasal obstruction and ostial occlusion were created. Furthermore, the effect of nasal obstruction in modulation of antral CO2 levels was found to be beyond its effect on hypoventilation of the sinus and to be independent of ostial functional status. We have established independent models of nasal obstruction and ostial occlusion in the same animal. Our findings suggest that ostiomeatal complex dysfunction might not be the sole underlying factor in the pathogenesis of sinus disease in all individuals. Integrity of nasal airflow seems to have a significant effect on the maintenance of the aerobic antral environment, essential to the maintenance of normal sinus function. Modulation of maxillary sinus gas composition by nasal airflow, independent of ostial patency, may be explained by the possible presence of flow-sensitive receptors in the upper respiratory tract mucosa. Work to identify such receptors is currently in progress.

Cardiac-specific overexpression of RhoA results in sinus and atrioventricular nodal dysfunction and contractile failure.

RhoA is a low-molecular-weight GTPase that has been implicated in the regulation of hypertrophic cardiac muscle cell growth. To study the role of RhoA in control of cardiac function in vivo, transgenic mice expressing wild-type and constitutively activated forms of RhoA under the control of the cardiac-specific alpha-myosin heavy chain promoter were generated. Transgene-positive mice expressing high levels of either wild-type or activated RhoA showed pronounced atrial enlargement and manifested a lethal phenotype, often preceded by generalized edema, with most animals dying over the course of a few weeks. Echocardiographic analysis of visibly healthy wild-type RhoA transgenic mice revealed no significant change in left ventricular function. As their condition deteriorated, significant dilation of the left ventricular chamber and associated decreases in left ventricular contractility were detected. Heart rate was grossly depressed in both wild-type and activated RhoA-expressing mice, even prior to the onset of ventricular failure. Electrocardiography showed evidence of atrial fibrillation and atrioventricular block. Interestingly, muscarinic receptor blockade with atropine did not elicit a positive chronotropic response in the transgenic mice. We suggest that RhoA regulates cardiac sinus and atrioventricular nodal function and that its overexpression results in bradycardia and development of ventricular failure.

A gastroesophageal electrode for electrophysiological studies.

A novel gastroesophageal electrode has been developed capable of atrial and ventricular pacing. We performed electrophysiological studies using the gastroesophageal electrode (Esothoracic) and compared the results with the standard endocardial approach. The flexible polythene gastroesophageal electrode was passed into the stomach under light sedation. Five ring electrodes, now positioned in the lower esophagus were used for bipolar atrial pacing and recording. Ventricular pacing was performed using a cathodic point source on the gastroesophageal electrode tip; the indifferent electrode (anode) was a high impedance chest pad. Parameters of sinus and AV nodal function were obtained by atrial pacing. Programmed ventricular stimulation was performed using a standard protocol. These electrophysiological parameters were subsequently determined using the endocardial approach. There was close correlation between measurements of sinus and AV node function using the two approaches in 48 subjects: sinus node recovery time (SNRT) r2 = 0.70, corrected sinus node recovery time (CSNRT) r2 = 0.87, AV Wenckebach cycle length (AVWCL) r2 = 0.97. The degree of agreement between the two approaches was estimated by the mean difference delta and standard deviation of the difference sigma (SNRT delta = 40 ms, sigma = 257 ms; CSNRT sigma = 14 ms, delta = 164 ms; AVWCL sigma = 7 ms, delta = 16 ms). Programmed ventricular stimulation was performed in 15 of 48 subjects with known or suspected ventricular tachyarrhythmias. Seven had ventricular tachycardia induced using both esothoracic and endocardial programmed ventricular stimulation. One subject was noninducible using esothoracic programmed ventricular stimulation, but inducible at endocardial electrophysiological studies. Another subject was inducible at esothoracic electrophysiological studies, but noninducible using endocardial programmed ventricular stimulation. Six subjects were noninducible using both endocardial and esothoracic programmed ventricular stimulation. The gastroesophageal electrode permits reliable atrial and ventricular pacing without transvenous catheterization or fluoroscopy. Electrophysiological parameters determined using this electrode are similar to those obtained using endocardial stimulation.

Transvenous Embolizations of Venous Compartments of Dural Arteriovenous Fistulas within Venous Sinus Walls

Transvenous embolization of venous compartments within the venous sinus wall was the method initially attempted for closing dural arteriovenous fistulas in 15 patients (22 sinuses). The venous channel, separate from the sinus lumen and located in the venous sinus wall, could be embolized in 6 lesions (3 patients), including 3 superior sagittal sinus fistulas, 2 transverse sinus fistulas, and 1 straight sinus fistula. This technique resulted in closure of the fistulas and preservation of sinus patency as well as immediate improvement of clinical symptoms. The embolizable venous compartment of the fistula within the venous sinus wall could be detected by preoperative angiography, magnetic resonance imaging, and intraoperative venography. This unique drainage of dural arteriovenous fistulas may develop concurrently with more obvious portions of the fistula. Transvenous embolization of these venous compartments can close the fistulas and normalize impaired sinus function.

Internal atrial defibrillation: effect on sinus and atrioventricular nodal function and implanted cardiac pacemakers.

Internal atrial defibrillation (IAD) has been extensively evaluated for clinical efficacy but the need for concomitant demand pacing and the effect of IAD shocks on pacemaker function is not well studied. We prospectively evaluated: (1) the incidence of bradycardia as a result of IAD shocks; and (2) effect of these shocks on functioning of implanted cardiac pacemakers. Consecutive consenting patients with atrial fibrillation (AF) requiring cardioversion or undergoing electrophysiological study were selected for IAD. IAD shocks were delivered using the right ventricle to right atrium (RV-RA), right ventricle to superior vena cava (RV-SVC), right atrium to axillary patch (RA-AX), and right atrium to left pulmonary artery or coronary sinus (RA-LPA/CS) lead configurations. Mean RR interval before and after the shocks and the time interval from shock delivery to first QRS complex were analyzed for unsuccessful and successful shocks. Pacing and sensing function was analyzed in patients with previously implanted pacemakers. Twenty-five patients, 18 men, mean age 67.9 +/- 10 years were included in the study. A total of 305 shocks (264 unsuccessful, 41 successful) were analyzed. For unsuccessful shocks the mean post-IAD shock RR interval (795 +/- 205 ms) and the time to first post-IAD shock QRS complex (970 +/- 438 ms) were both significantly greater than the pre-IAD shock RR interval (685 +/- 131 ms, P < 0.001). The increase in post-IAD shock RR interval and time to first post-IAD shock QRS complex was seen with all four lead configurations used. With successful shocks the mean post-IAD shock sinus cycle length (1,105 +/- 450 ms) and time to first post-IAD shock QRS complex (1,126 +/- 443 ms) were both also significantly greater than the pre-IAD shock RR interval (766 +/- 172 ms). Nine patients (36%) had episodes of significant bradycardia after shock delivery. Shocks of up to 20 J using the RA-LPA/CS lead configuration did not affect pacemaker function. IAD can result in transient bradycardia related to sinus and atrioventricular nodal effects requiring backup ventricular pacing. Shocks can be safely delivered using RA-LPA or RA-CS lead configurations in patients with implanted bipolar cardiac pacemakers.