Cadaver Studies of the Anatomy of Arterial Supply to the Inferior Turbinates

The anatomy of the arterial supply of the inferior turbinate was studied by dissection and serial histological sections. The arrangement was found to be constant, with a single main descending branch of the sphenopalatine artery entering its substance from above, 1–1.5 cm from its posterior border. This artery branches as it passes forwards within the turbinate, remaining close to the bone. As these pass anteriorly they give rise to arterial arcades which remain close to or within the bone, with the main artery increasing in diameter. The implications of these findings are discussed in a surgical context.

Why Rudolph's nose is red: observational study

OBJECTIVE

To characterise the functional morphology of the nasal microcirculation in humans in comparison with reindeer as a means of testing the hypothesis that the luminous red nose of Rudolph, one of the most well known reindeer pulling Santa Claus's sleigh, is due to the presence of a highly dense and rich nasal microcirculation.

DESIGN

Observational study.

SETTING

Tromsø, Norway (near the North Pole), and Amsterdam, the Netherlands.

PARTICIPANTS

Five healthy human volunteers, two adult reindeer, and a patient with grade 3 nasal polyposis.

MAIN OUTCOME MEASURES

Architecture of the microvasculature of the nasal septal mucosa and head of the inferior turbinates, kinetics of red blood cells, and real time reactivity of the microcirculation to topical medicines.

RESULTS

Similarities between human and reindeer nasal microcirculation were uncovered. Hairpin-like capillaries in the reindeers' nasal septal mucosa were rich in red blood cells, with a perfused vessel density of 20 (SD 0.7) mm/mm(2). Scattered crypt or gland-like structures surrounded by capillaries containing flowing red blood cells were found in human and reindeer noses. In a healthy volunteer, nasal microvascular reactivity was demonstrated by the application of a local anaesthetic with vasoconstrictor activity, which resulted in direct cessation of capillary blood flow. Abnormal microvasculature was observed in the patient with nasal polyposis.

CONCLUSIONS

The nasal microcirculation of reindeer is richly vascularised, with a vascular density 25% higher than that in humans. These results highlight the intrinsic physiological properties of Rudolph's legendary luminous red nose, which help to protect it from freezing during sleigh rides and to regulate the temperature of the reindeer's brain, factors essential for flying reindeer pulling Santa Claus's sleigh under extreme temperatures.

The clinical value of the novel cauterization procedure for the inferior turbinate artery during turbinate surgery

The objective of the study was to evaluate the efficacy and the safety of the novel cauterization procedure of the inferior turbinate artery, which may be performed with any kind of inferior turbinate procedures in reducing the intra and the post-operative bleeding in partial inferior turbinectomy. A prospective controlled study was conducted in a referral center. Sixty patients (38M, 22F) who underwent partial turbinectomy were included. In 20 patients, partial turbinectomy was performed with the cauterization in one nasal cavity and the other one without it. The remaining 40 patients were divided into two groups which comprised cauterization positive and negative patients and are assessed in terms of post-operative bleeding. The area of the cauterization was 1 cm(2) field which is 1 cm anterior to the posterior attachment of the inferior turbinate on the lateral nasal wall, very close to the inferior turbinate, where the pulsating vessel is most commonly seen. Mean operation time, mean intra-operative blood loss and post-operative bleeding incidence are the main outcome measures. Post-operative bleeding was seen in three patients (15%) in the cauterization negative group. No patient had post-operative bleeding in the cauterization positive group. Mean operation time and mean intra-operative bleeding amount were significantly lower in the cauterization positive side. Cauterization of the inferior turbinate artery on the lateral nasal wall is a safe and effective method which may also be performed with any kind of inferior turbinate procedures to reduce both the operation time and intra and post-operative bleeding.

[The influence of different methods of surgical intervention on mucosal microcirculation in the inferior turbinate bone evaluated by laser Doppler flowmetry]

Thirty patients with enlarged inferior turbinate bones were allocated to 3 subgroups depending on the choice of surgical treatment. The control group comprised 10 practically healthy volunteers with unaffected nasal and paranasal cavities. The objective of the study was to compare clinical efficiency of three surgical techniques, viz. submucosal vasotomy, submucosal endoscopic conchotomy, and submucosal osteoconchotomy. Mucosal microcirculation in the nasal cavity was studied by laser Doppler flowmetry in the middle part of the inferior turbinate bone. In all the cases, measurements were performed before and after the adrenaline test; patients of the study group underwent additional measurements on day 7 and 3 months postoperatively. The results of the study confirmed the development of microcirculatory disturbances in patients with enlarged inferior turbinate bones. It is concluded that all the three surgical modalities employed in this study for the correction of enlarged inferior turbinate bone preserve functional capacity of intranasal mucosa and promote normalization of its microhemodynamic patterns. Submucosal endoscopic conchotomy appears to be the most efficacious of the three techniques.

Regional differences in vascular responsiveness of nasal mucosae isolated from naive guinea pigs

OBJECTIVE

In the present study, the contractile response to norepinephrine (NE) and relaxing response to histamine and leukotriene D(4) (LTD(4)) were compared among the nasal mucosae of septa (S) and lateral (L) and medial turbinates (M) isolated from naive male Hartley guinea pigs.

METHODS

The isometrical tension of the isolated nasal mucosae of the above regions was measured at a resting tension of 0.5 g by using a standard organ-bath technique.

RESULTS

In each mucosal strip, NE induced a contraction in a concentration-dependent manner. A significant difference in efficacy (maximal response) of NE was found (L>M>S). In mucosal strips precontracted with NE (3x10(-5)M), both histamine and LTD(4) induced relaxing responses. The efficacy of histamine in S was significantly greater than those in L and M. The potency order of LTD(4) was L>M>S; a significant difference was observed between L and S.

CONCLUSION

In conclusion, the present study demonstrated a distinct regional difference in the response to contractile and relaxant agonists of isolated nasal mucosae of guinea pigs.

Variability of vascularity in nasal mucosa as demonstrated by CD34 immunohistochemistry

Regional anatomical variations in the nasal vasculature have not been studied histologically. Immunohistochemistry performed using marker for CD34 antigen on vascular endothelium biopsied from 5 sites on the lateral nasal wall and compared with one septal biopsy. No significant regional variations in microvascular architecture over the lateral wall of the nose were found. * Lateral wall measurements were significantly different to the septal measurements (P = 0.0003, 0.01). Suggests biopsies can be taken from any site on the lateral wall and give a representative sampling of the vascularity for research purposes.

Different swelling mechanisms in nasal septum (Kiesselbach area) and inferior turbinate responses to histamine: an optical rhinometric study

OBJECTIVE

To determine whether the inferior turbinate, which contains swelling bodies, and the nasal septum (Kiesselbach area), characterized by a dense arterial mesh, exhibit different swelling mechanisms in allergic nasal reactions.

DESIGN

Two optical rhinometers were used to examine 11 patients in the clinic. Optical rhinometry is based on the transillumination of the nasal septum and inferior turbinate or the whole nose with monochromatic light. The instrument's wavelength can be adjusted to the absorption characteristics of reduced hemoglobin, oxygen-saturated hemoglobin, and water.

SETTING

Outpatient university otolaryngology clinic.

PATIENTS

Eleven young, healthy, nonsmoking, nonpregnant subjects (6 men and 5 women), mean age, 32.4 years (age range, 27-37 years), with no history of exposure to toxic substances, allergies, or other significant diseases.

INTERVENTIONS

Optic rhinometry evaluation during the course of nasal histamine administration.

MAIN OUTCOME MEASURES

Light extinction at various wavelengths.

RESULTS

Following administration of histamine, in the nasal septum, the wavelength of 950 nm (edema) showed the strongest increase of light extinction; in the inferior turbinate, it was the wavelength of 786 nm (oxygenated hemoglobin). In the whole nose, the wavelength of 880 nm (edema plus hemoglobin) exhibited the largest increase of extinction.

CONCLUSIONS

Swelling of the nasal septum (Kiesselbach area) in nasal allergic reactions is caused mainly by edema, whereas swelling of the inferior turbinate is due mainly to an increase in volume of blood that is highly saturated with oxygen. Swelling of the whole nose is characterized by the combination of both, edema and increase in blood volume.

Inferior Turbinate Arterial Supply: Histologic Analysis and Clinical Implications

OBJECTIVE

To study the arterial architecture of the normal inferior turbinate.

DESIGN

A prospective, nonrandomized, histologic study.

MAIN OUTCOME MEASURES

Fourteen samples were removed at autopsy and during septoplasty operations, processed in the usual manner, stained with hematoxylin-eosin, and investigated microscopically. The analysis included data on the number, location within or outside the bone, the mean area, wall thickness, and distance the arteries traverse from the point of entrance into the bone to the point of exit into the soft tissue.

RESULTS

One to three arteries enter the inferior turbinate posteriorly. In 7 of 14 inferior turbinates (50%), the arteries lie within the bone and in 2 (14%) within the soft tissue, and in 5 (36%), a mixed pattern was observed. The arteries run along a mean of 1.2 +/- 0.49 cm before piercing the bone into the soft tissue and split off to one to six branches. The mean area and the mean wall thickness of the arteries at the entrance into the bone posteriorly were significantly greater than that of the arteries emerging from the bone and entering the soft tissue anteriorly (0.099 +/- 0.056 mm2 vs 0.051 +/- 0.022 mm2 [p < .01] and 0.116 +/- 0.042 mm vs 0.083 +/- 0.031 mm [p < .05], respectively). The inferior mucosal layer lacks major arteries.

CONCLUSION

Given the data presented here, the excision of the inferior mucosal layer and the anterior portion of the inferior turbinate bone distal to the point of arterial exit constitute a relatively low risk for postoperative arterial bleeding.

[NPY in human nasal mucosa -- an immunocytochemical and immunoelectron microscopical study]

BACKGROUND

The functions of the nasal mucosa are regulated by numerous endogenous and exogenous influences. The innervation patterns are important for the control of the physiological nasal functions. In addition to the classic neurotransmitters different neuropeptides might play a regulating and modulating role in the nasal mucosa. Both the significance and the localization of neuropeptide Y (NPY) have not been fully elucidated.

PATIENTS AND METHODS

Tissue samples of human inferior turbinates from 42 patients were taken during nasal surgery and preserved in phosphate-buffered paraformaldehyde or glutaraldehyde. Serial sections were incubated with antibodies against NPY and the ABC method was applied. In order to identify immunoelectron microscopic reactions a streptavidin-gold-marker was used. The findings were photodocumented by using a light- and transmission-electron microscope.

RESULTS

NPY-positive terminals were mainly located in the adventitia of arterial vessels. There were also NPY-immunoreactive arterioles near to the glands. Periglandular a lower density of immunoreactions could be observed. NPY-positive fibers could be detected in the subepithelial connective tissue and at the glandular ducts. Immunoelectron microscopy revealed NPY within periglandular axons.

CONCLUSIONS

Immunohistochemical and immunoelectron microscopical methods allow a detailed identification of the sympathetic cotransmitter NPY in arterial vessels of nasal mucosa in man. These results indicate that NPY-containing nerve fibers innervate arteries as well as nasal glands. These findings suggest that NPY play a significant role as a neuromodulator in the control of both vasculature and glandular secretion. The localisation of NPY in periglandular and periductal nerves confirms the direct influence of glandular functions. NPY-agonists may be a beneficial additional treatment of rhinopathies to reduce nasal obstruction and mucus secretion.

Anatomic variations of the arteries of the nasal fossa

OBJECTIVE

This study was performed for knowledge about the vascular supply of the nasal fossa and a description of the site of division and number of branches of the sphenopalatine artery.

STUDY DESIGN

This study was performed on 10 fresh nonembalmed cadavers. Anatomic variations of nasal fossa arteries were studied.

METHODS

First, 10 cephalic anatomic preparations were injected with red color latex into the right and left carotid arteries. Then, these specimens were sagittaly cut to dissect the sphenopalatine artery. Twenty vascularization cases were studied for the external branch of the sphenopalatine artery, and 10 cases were studied for the internal branch.

RESULTS

The principal observations were: 1. the sphenopalatine artery division is 18 times in the infratemporal fossa and twice in the nasal fossa; 2. the nasopalatine artery supplies blood to the lower part of the septum and its anterosuperior area; and 3. the vascularization of the external wall is via the sphenopalatine artery through the arteries of the meatus and conchae.

CONCLUSION

This study defines the vascular territories of the nasal fossa arteries and includes photographs of dissections.

Surgical anatomy of the sphenopalatine artery in lateral nasal wall

OBJECTIVE

We investigated the surgical anatomy of the sphenopalatine artery. First, the location of the sphenopalatine foramen on the lateral nasal wall and the pattern of the main branches of the sphenopalatine artery from the sphenopalatine artery were studied. Second, the course of the posterior lateral nasal artery with respect to the posterior wall of the maxillary sinus, the perpendicular plate of the palatine bone, and the pattern of distribution of its branches on the fontanelle was determined. Third, the distribution pattern on the inferior turbinate was analyzed.

STUDY DESIGN

Fifty midsagittal sections of randomly selected Korean adult cadaver heads with intact sphenoid sinus and surrounding structures were used in the study.

METHODS

The mucosa on the sphenopalatine foramen and its surrounding mucosa were removed with a microscissors, a fine forceps, and a pick to expose the sphenopalatine artery under an operating microscope (original magnification x6).

RESULTS

The feeding vessels of the superior turbinate were from the septal artery in 36 cases (72%). The feeding vessels to the middle turbinate branch originated from the proximal portion of the posterior lateral nasal artery just after exiting the sphenopalatine foramen in 44 cases (88%). Some portion of the posterior lateral nasal artery ran anterior to the posterior wall of the maxillary sinus in 38%. The major feeding arteries to the fontanelle were from the inferior turbinate branch in 25 cases (50%). In most cases, the inferior turbinate branch was the end artery of the posterior lateral nasal artery (98%).

CONCLUSIONS

The study provides detailed information concerning the sphenopalatine artery, which we hope will help explain the arterial bleeding that may occur during ethmoidectomy, middle meatal antrostomy, conchotomy, and endoscopic ligation of the sphenopalatine artery.

[Regulation of the swelling mechanism in the inferior turbinate of human nasal mucosa]

BACKGROUND

The swelling mechanism of human nasal mucosa is based on a complicated vascular system and regulated by a variety of classical and peptidergic transmitters as well as by endothelial transmitters. The aim of this study was to elucidate this mechanism taking into account the distribution of these substances and the morphology of the different vessels.

METHODS

Tissue specimens of human inferior turbinates were evaluated by light and electron microscopy. We used frozen sections to localize enzymes of the transmitter synthesis by histochemical and immunocytochemical methods. The distribution of classical neurotransmitters, neuropeptides (calcitonin-gene-related-peptide, neuropeptide Y, substance P and vasoactive intestinal polypeptide), enzymes producing neuronal NO (neuronal nitric oxide synthase, nicotine-amid-adenine-dinucleotide-phosphate-diaphorase) as well as endothelial transmitters such as endothelin and endothelial nitric oxide were examined. For ultrastructal examination the specimens were fixed in glutaraldehyde und osmium tetroxide, embedded in araldide, cut and double contrasted.

RESULTS

Most of the axons and immunoreactivity of transmitters were located in the arterial part of the human nasal vascular system. In venous vessels only a spare innervation was observed, whereas in the subendothelial muscular bolsters of the cushion veins a rich nerve supply could be detected. Near the fenestrated subendothelial and periglandular capillaries no axons were found. Nasal vasculature is supplied by a equilibrated aminergic and cholinergic innervation. Mainly arterial vessels showed reactions to antibodies directed against endothelial transmitters.

CONCLUSION

Because of the dense innervation of arteries and subendothelial venous muscular bolsters we conclude that the swelling mechanism of human nasal mucosa is mainly regulated by these structures. A dual (endothelial and neuronal) control exists in arterioles whereas the control in the subendothelial muscular swellings of the cushion veins appears to be mainly neuronal. The swelling of the nasal mucosa is achieved by an simultaneous relaxation of all smooth muscle cells, which leads to dilatation of arteries as well as venous sinuses. The drainage of the vascular bed is reduced by the venous muscular bolsters protruding into the lumen of the venous sinuses. Vice versa, a contraction of all smooth muscle cells leads to a contraction of the arteries and, consecutively, to a reduction of blood supply. Simultaneously the muscular bolsters are torn out of the lumen of venous sinusoids allowing blood drainage to be increased: nasal concha decongests.

Merkel cell carcinoma: a rare cause of hypervascular nasal tumor

Cutaneous neuroendocrine carcinoma, first described in 1972, is an aggressive disease usually occurring in sun-exposed skin. Other sites have been described, however; such tumors occasionally occur within the nasal fossa. A high rate of metastasis (>30%) explains the poor prognosis. Descriptions of the imaging features of these tumors, mainly located in cutaneous region, are rare. We therefore present the imaging features of two cases of Merkel cell carcinoma involving the sinonasal region, suggestive of a hypervascular tumor.

Endoscopic ligation of anterior ethmoidal artery in treatment of epistaxis

Arterial ligation of the anterior ethmoidal artery may be required in cases of persistent epistaxis and conventional techniques involving open surgery carry a recognized morbidity. We describe an endoscopic, intranasal technique for ligation of the anterior ethmoidal artery. This technique was performed in a patient who had a severe epistaxis following nasal trauma. Her epistaxis persisted in spite of anterior and posterior nasal packing. Endoscopy showed the bleeding to originate high and lateral to the middle turbinate. Endoscopic exploration defined the frayed end of the anterior ethmoidal artery. A ligaclip was placed with immediate and persistent arrest of her epistaxis. No further nasal packs or treatment were required.

Nasal airflow in health and disease

This review examines our present understanding of the physiology, pathophysiology and pharmacology of nasal airflow. The main aim of the review is to discuss the basic scientific and clinical knowledge that is essential for a proper understanding of the usefulness of measurements of nasal airflow in the clinical practice of rhinology. The review concludes with a discussion of the measurement of nasal airflow to assess the efficacy of surgery in the treatment of nasal obstruction. Areas covered by the review include: influence of nasal blood vessels on nasal airflow; nasal valve and control of nasal airflow; autonomic control of nasal airflow; normal nasal airflow; nasal cycle; central control of nasal airflow; effect of changes in posture on nasal airflow; effect of exercise on nasal airflow; effect of hyperventilation and rebreathing on nasal airflow; nasal airflow in animals; cerebral effects of nasal airflow; sensation of nasal airflow; sympathomimetics and sympatholytics; histamine and antihistamines; bradykinin; and corticosteroids.

The septal mucosa decongests with naphazoline: a study of mucosal dynamics with sonography

A new method using B-mode and power-Doppler-mode (pD) sonography for the investigation of changes in nasal mucosa swelling and perfusion was developed. The effect of naphazoline (0.25 mg/mL) on the nasal mucosa was visualized and recorded in 1-minute intervals in 40 patients. The effect of normal saline solution was studied in 27 healthy volunteers. The decongestant and normal saline were applied by flooding the anterior nasal cavity. A computer program automatically quantified pD color information. Normal saline solution induced a 4.8 +/- 2.4% increase in perfusion (+/- SEM, n.s.) after 5 minutes. In the naphazoline group, changes in stereometry were measured on B-mode-sequences in 24 (60%) and perfusion changes in 24 participants (60%). In 16 of 40 patients (40%), both stereometry and perfusion were analyzed. After 10 minutes, the septum and inferior turbinate mucosa thickness were reduced by 17 +/- 2.8% (p < 0.001) and 25 +/- 2.6% (p < 0.001). Perfusion of the septum and inferior turbinate mucosa as visualized with pD-sonography decreased by 33 +/- 3.3% (p < 0.001). The reduction of bloodflow induced by naphazoline as visualized with pD-sonography is within the range of perfusion changes found in LDF and Xenon clearance studies. Decongestion of the septum mucosa demonstrates erectile properties of the septum, which may contribute to the increase of nasal patency after nasal decongestion.

Nasal reconstruction using the inferior turbinate mucosal flap

Reconstruction of nasal defects can be a difficult task if large amounts of nasal mucosa are missing. We have found the inferior turbinate mucosal flap to be a reliable and effective flap in a series of 16 patients undergoing nasal reconstruction or repair of septal perforations. Most of these patients had insufficient mucosa to use traditional flaps harvested from the nasal floor or the lateral nasal wall. Eight patients underwent reconstruction of septal perforations, 9 patients underwent nasal reconstruction of large nasal defects after tumor extirpation, and 1 patient underwent closure of a palatal fistula. Six of the septal perforations were closed completely and 3 were reduced in size by 50%. All 11 turbinate flaps used for nasal reconstruction (2 patients had bilateral flaps) survived. Two flaps underwent mild superficial epidermolysis without flap necrosis or exposure of overlying cartilage grafts. The turbinate flap is based anteriorly and provides large amounts of well-vascularized mucosa. The turbinate is rotated anteriorly and bivalved and the conchal bone is removed to increase the dimensions of the flap. The flap is sometimes staged to allow transfer of mucosa to distant sites, such as the septum, the nasal ala, and the nasal wall. An anatomical dissection of 10 turbinate flaps on 5 fresh cadaver specimens demonstrated an average flap size of 4.97 cm2. The average length of the flap was 2.83 cm, which is sufficient length to reach the nasal dorsum. A description of the surgical technique and the vascular supply of this flap will be discussed.

Innervation of nasal turbinate blood vessels in rhinitic and nonrhinitic children

An immunohistochemical study of the nasal mucosa was done in pediatric patients attending an otorhinolaringology (ORL) clinic. The goal was a comparison between vascular innervation in patients with or without symptoms of chronic rhinitis. All patients had an indication for tonsillectomy prior to their inclusion in this study. Samples were obtained under general anesthesia at the time of programmed surgery and fixed in a paraformaldehyde-picric acid mixture. Cryostat sections were immunostained for the following neuronal markers: protein-gene product 9.5 (PGP), calcitonin gene- related peptide (CGRP), substance P (SP), and C-terminal peptide of neuropeptide Y (CPON). The following classes of vessels were identified: arteries, sinusoids, veins, and arteriovenous anastomoses (AVAs). As shown by immunostaining with the general neuronal marker PGP, each vessel type had a characteristic innervation pattern, differing in the amount of fibers and their distribution within the adventitial and muscle layers. Evaluation of PGP, CPON, and CGRP immunoreactivity patterns indicated that rhinitic arteries and AVAs displayed a richer innervation than did nonrhinitic blood vessels. Quantification of vascular PGP immunostaining confirmed the difference of vascular innervation between nonrhinitic and rhinitic patients. Fibers immunostained by CPON partially accounted for the rhinitic arterial hyperinnervation.

[Power Doppler and B-mode sonography of nasal mucosa]

Anatomy and perfusion of the nasal septum and inferior turbinate mucosa can be visualized with B-mode and power-Doppler ultrasound. The transducer is placed externally on the nasal ala parallel to the pyriform crest and directed towards the head of the inferior turbinate of the opposite side. An individually prepared dental splint keeps the transducer in position and allows assessment of dynamic changes in mucosal swelling and perfusion. Perfusion changes are evaluated by computerized quantification of power-Doppler color pixels. Coupling of ultrasound across the nasal lumen is achieved by introducing gel into one nasal vestibule and flooding the anterior nasal cavity of the side to be visualized with isotonic aqueous solutions. Perfusion could be visualized in 23 of 30 subjects, while B-mode sonographic anatomy was visualized in 16 subjects. The effect of isotonic saline solution (10 healthy subjects), naphazoline (10 patients with chronic nasal obstruction) and allergen extracts (10 patients with allergic rhinitis) on mucosal perfusion and swelling was studied. Isotonic saline solution induced a maximum drop in power-Doppler color pixel density by 10% and a maximum increase by 27%, but no change was seen in mucosal swelling. Naphazoline induced a 10-57% decrease in power-Doppler pixel density and decongestion of the inferior turbinate and septum mucosa by 17-43% and 4-27%, respectively. Allergen extracts induced an increase in power-Doppler color pixel density by 24-181% and an increase in mucosal thickness by 4-31%. These preliminary results encourage further studies of nasal mucosal perfusion changes using power-Doppler sonography after pharmacologic and allergen provocations.

Osteologic classification of the sphenopalatine foramen

Textbook descriptions and illustrations of the opening of the sphenopalatine foramen (SPF) into the nasal cavity place it above and behind the posterior end of the middle turbinate (i.e., within the superior meatus). Although true for some skulls, this is not the situation for the majority and may be of importance, because the major blood supply to the nasal cavity enters via this route. Having studied 238 lateral nasal walls, the authors propose a classification of the osteology of the sphenopalatine foramen. In class I (35%) the opening of the SPF is purely into the superior meatus with a notch or foramen in the middle turbinate/ethmoidal crest of the palatine bone. In class II (56%) the SPF spans the ethmoidal crest (i.e., opens into both the superior and middle meati). In class III (9%) there are two separate openings into the superior and middle meati. These findings may explain the route of the artery to the inferior turbinate and indicate the need for care in dealing with the posterior end of the middle turbinate. They may also suggest a potential site for dealing with "difficult" epistaxis via an intranasal route.

The impact of the measuring distance on laser-Doppler measurements of the microcirculation in human nasal mucosa. A study of rhinostereometry and micromanipulator-guided laser-Doppler flowmetry

Fourteen healthy volunteers were examined using rhinostereometry (RSM) and micromanipulator-guided laser-Doppler flowmetry (LDF) on the inferior turbinate and nasal septum. There were significant differences of the flowmetry readings at different distances from the mucosal surface within 0-1.0 mm. Changes in LDF values due to a change in distance between probe and mucosa seem to be an important artefact that will influence the flowmetry, especially if the probe is fixed to the framework of the nose (i.e. the skull) and if the congestive status of the mucosa changes. This can be a problem especially during intranasal challenges with substances that influence congestion. These artefacts can be eliminated by using an RSM-guided micromanipulator that allows the probe to follow changes in congestion.

Intracellular Ca2+ mobilization in cultured human mucosal microvascular endothelial cells from the nasal inferior turbinate

Human mucosal microvascular endothelial cells (HMMECs) were isolated and cultured from the mucosa of nasal inferior turbinates. These cells were identified by human factor-VIII antigen and UEA-I. We also investigated alterations in intracellular calcium concentration [Ca2+]i, in HMMECs using the Ca(2+)-sensitive dye fura-2. Depolarization by high K+ (150 mM) induced no changes in [Ca2+]i in HMMECs, thereby indicating the lack of voltage-dependent Ca2+ channels in these cells. Extracellular ATP increased [Ca2+]i in HMMECs both in the presence and absence of extracellular Ca2+. These results suggest that ATP may induce a release of Ca2+ from intracellular stores in HMMECs. Adenosine induced no changes in [Ca2+]i in HMMECs. It is thus likely that HMMECs obtained from the nasal inferior turbinate may carry P2-purinoceptors but not P1-purinoceptors.

Redistribution of cardiac output in response to heat exposure in the pony

Radioactive microspheres were used to measure cardiac output and blood flow to most major tissues in 4 ponies at rest in thermoneutral (16 degrees C/60% RH) and mildly hot (41 degrees C/34% RH) environments. In response to heat stress there were increases in cardiac output (2-fold), respiratory frequency (5-fold), blood flow to the skin of the body (3-fold), and limbs (50%), respiratory muscles (2-fold) and the upper respiratory tract (3-fold). Ponies were able to maintain body temperature in the hot environment by increasing blood flow to the tissues involved in heat dissipation, while blood flow to all other tissues remained stable. This was achieved by increasing the cardiac output without need for reduction of blood flow to other tissues.

Intervascular smooth muscle fibers and muscular bolsters in nasal swell bodies of humans

There is strong clinical evidence that the cavernous tissue (swell bodies) of nasal mucosa plays an important role in congestion of the nose. Still, the complex mechanisms responsible for the unique behavior of these vessels have not yet been identified, and even the morphology of these structures is still a matter of controversy. The present study was performed on nasal mucosal specimens from inferior turbinates of humans by means of histology and transmission electron microscopy. Besides the evaluation of the vascular wall structure of the nasal swell bodies, special attention was given to two morphological peculiarities: intervascular smooth muscle fibers and muscular bolsters. Intervascular smooth muscle fibers are composed of bundles of smooth muscle cells varying in diameter between 14 and 35 microns; they are attached to the muscular coat of the vessels of the cavernous tissue. Muscular bolsters are distinct protrusions of the vascular wall in nasal swell bodies; they are found not only at the transition between different vessels, but also irregularly within the course of veins of the cavernous tissue. The authors report on their understanding of the functional significance of intervascular smooth muscle fibers and muscular bolsters within the cavernous tissue for swelling mechanisms in the nose and discuss their results in light of the literature.

[The morphology of endonasal cavernous tissue with special reference to muscular cushion formation. A light and transmission electron microscopy study]

Nasal "cavernous" tissue is widely accepted as a key structure for the tumefactive mechanism inside the nose; still there is no common understanding of the structural composition of this special tissue. In the present paper the authors demonstrate the results of their histological and transmission electronmicroscopic findings in human nasal "cavernous" tissue, especially referring to the structural and ultra-structural pattern of the so-called muscular pads or "cushion". Serial sections revealed that these structures occur at the transition of communicating vessels; their muscular coat shows a different and irregular pattern, compared to the vascular wall structure of other parts of nasal "cavernous" tissue. Ultrastructural examination confirmed the impression of a variable and complex orientation of smooth muscle cells within the muscular "cushions". The cytoplasmic components, however, were the same as in other smooth muscle cells of nasal "cavernous" tissue. Localisation and structure of muscular "cushions" imply their functional significance for tumescence of the nasal mucosa in a variety of rhinological disorders. Therefore, the authors suggest to include these special features in therapeutic considerations on the treatment of congested nose. Evaluation of the neurovegetative regulation of this tissue could be a step in the right direction.

[Site-specific, structural and ultrastructural characteristics of endonasal cavernous tissue exemplified by the inferior turbinate in man. Light and transmission electron microscopy study]

The cavernous tissue of the nose has been studied morphologically for now more than 150 years. Even though the majority of new findings was already described in the second half of the last century and is associated with scientists like Kölliker, Kohlrausch and Zuckerkandl. The vascular structures, usually described as "cavernous tissue" or "swell bodies" are located in different parts of the nasal mucosa, but mainly in the inferior turbinate. In the present paper the author demonstrates the results of his studies on the structure and ultrastructure of smooth muscle components of nasal swell bodies based on light - and transmission-electron microscopic findings. Light microscopic observations already reveal the differences in vascular wall structure between areas adjacent to the epithelium and those parts of the vessels located in the deeper parts of the tunica propria. Ultrastructural examination shows differences in size and density of smooth muscle cells in different parts of the cavernous tissue; it also demonstrates the variant appearance of the basal lamina of these muscle cells. The results are discussed and compared with the appropriate literature.

[Immunohistochemical study of the neuroanatomy of the nasal turbinate in man. Innervation pattern of the blood vessels]

The complex vasculature of the human nasal mucosa plays an important role in the protection of the lower respiratory airways. It has to react to different external and internal stimuli and is under control of the autonomic nervous system. The aim of our study was to detect the precise localisation of neural structures in human nasal mucosa vessels under physiological conditions. Silver impregnation and histochemical staining techniques only allowed a partial aspect of autonomic innervation. Modern immunostaining methods with antibodies to neuron-specific enolase (NSE) and S-100 protein proved to be better for the demonstration of nerve structures. Tissue samples were taken from inferior turbinates received at mucotomy in 42 patients. After fixation the samples were embedded in paraffin wax and cut into serial sections. Additionally frozen sections were performed. The immunocomplexes were visualised by the avidin-biotin-complex (ABC) or by the alkaline phosphatase anti-alkaline phosphatase (APAAP) technique. A high density of S-100 and NSE immunoreactivity of neuronal and glial components of autonomic innervation could be demonstrated in the vessels of human nasal turbinates. Branching off relatively thick nerve bundles of the lamina propria fibres extended to the adventitia of the arteries near the periost and formed a periarterial nerve plexus. Fibres of this plexus supplied the smooth muscle tissue of the tunica media. Around veins only a few single nerve fibres could be demonstrated. By using immunocytochemical techniques it is possible to correlate the localisation of the classical neurotransmitters and multiple vasoactive neuropeptides with the corresponding innervation structures of the complex vasculature in human nasal mucosa.

Plasma endothelin-1 concentration in the inferior turbinate

Endothelin (ET)-1 has the most potent vasocontrictive action of any substance known to date. Three milliliters of blood was removed from both the inferior turbinate and from the antecubital vein of six patients who underwent nasal surgery under general anesthesia. After centrifugation of the blood samples, the plasma was sent for radioimmunoassay of the plasma levels of ET-1. The plasma ET-1 level in the nasal blood vasculature was 6.4 +/- 1.0 pg/mL (mean +/- SEM), which was almost equivalent to that found in the antecubital vein (5.3 - 2.7 pg/mL) (N = 6). These values were greater than the normal range (1.5 +/- 0.5 pg/mL) probably because of the effect of general anesthesia. These results indicate that ET-1 is present in similar levels in the blood vessels of the inferior turbinate and the antecubital vein. A hypothesis that adrenaline induces ET production was not confirmed because topically applied adrenaline did not raise the plasma ET-1 level either in the nasal vasculature or in the peripheral vein.

'Priapism' of the turbinates: a cause of nasal obstruction in sickle cell anaemia

A cause of nasal obstruction in sickle cell anaemia not previously described in the literature is presented. The pathophysiology is the same as in priapism because of the similarities in the vascular arrangement of the turbinate and the penis. Various treatment options are considered but the best results were achieved by surgical reduction of the inferior turbinates.

An anatomical investigation of the nasal venous vascular bed in the dog

Physiological experiments have demonstrated that the canine nasal mucosa has two venous systems that differ in blood pressure and flow. An investigation of the vascular arrangements and histological characteristics of the nasal venous vascular bed was performed to search for anatomical structure(s) responsible for their functional separation. Parietal bicuspid valves were found to be present in both venous systems, being particularly abundant at the two extremities of the nasal cavity and less frequently found over the turbinates. Ostial valves were found to be present guarding the entries of tributaries into the periosteal venous plexus, collecting veins and outflow veins of the nasal mucosa. The collecting veins of the posterior venous system were found to be much larger and to contain a greater amount of muscle than those of the anterior venous system. The parietal valves are suggested to be the anatomical structures responsible for the functional separation of the two venous systems whereas the ostial valves might act as a throttle mechanism, regulating blood flow into the cavernous periosteal venous plexus and the collecting veins of the posterior venous system. The physiological significance of the presence of venous valves and their distribution in the nasal mucosa as well as the probable functions of the collecting veins of the posterior venous system are discussed.

Establishment of human mucosal microvascular endothelial cells from inferior turbinate in culture

Human microvascular endothelial cells were isolated and cultured from the mucosa of inferior turbinates. Using dish-coated collagen and a medium composed of a 1:1 mixture of sarcoma 180-conditioned medium and Dulbecco's modified Eagle's medium (containing 10% fetal bovine serum and 75 micrograms/mL endothelial cell growth factors prepared from bovine pituitary glands), these cells grew rapidly to confluence and survived serial passages until the 16th population doubling level. The cells were identified as endothelial cells by their morphology, immunostaining of factor VIII antigen, and cytochemical staining with Ulex europeus agglutinin. Furthermore, Weibel-Palade bodies and numerous pinocytotic vesicles were confirmed by electron microscopy. Proliferation experiments demonstrated the need for either endothelial cell growth factor or tumor-conditioned medium. An exogenous matrix was also required for these cells in tissue culture. A tubule-like morphology appeared in the original monolayer of human microvascular endothelial cells after 1 month in the same plate, indicating that these cells have the ability to form tubules in the presence of sarcoma 180-conditioned medium.

Vascular corrosion casts of the nasal mucosa. An experimental study in the rabbit

Ten-rabbits of either sex, weighing between 1.8 and 2.7 kg were used for studies on the angioarchitecture of the nasal mucosa of the septum and the anterior concha. Via the common carotid artery, Batson's corrosion compound No. 17 was introduced into the vascular system of the nose after rinsing with Ringer's solution. After digesting the connective tissue between the vessels, vascular corrosion casts were obtained. The replica of the endonasal angioarchitecture offers a unique opportunity to examine the various vascular layers of the nasal mucosa as well as the junction and relationships between different vessels in the different levels of the tunica propria. Our results can be regarded as a useful extension of earlier investigations in this field.

MR demonstration of the nasal cycle in the beagle dog

Magnetic resonance (MR) imaging of periodic engorgement of the erectile tissue surrounding the turbinates in the beagle dog yields remarkably quiet data that are well fitted by a single sinusoidal wave form. This observation holds in spite of right-left asymmetries in the distribution of the MR signal. The nasal cycle also occurs normally in humans. Judging from the clarity of its MR representation in the dog, it is possible that this phenomenon could be confused in human MR with upper respiratory congestion associated with pathological processes.

[Cavernous tissue of the nasal mucosa]

The "cavernous" tissue of the nasal mucosa possesses a key function for different physiological and pathological conditions. In the present study we report about our own examinations on the "cavernous" tissue of the rabbit nasal mucosa. The specimen (nasal septum and anterior concha) were fixated by vascular perfusion via the carotid arteries, carefully excised and prepared for light and electron microscopy. Our observations indicate that the tunica propria of the nasal mucosa is covered by large, sinusoidal veins. Most of these vessels possess a rather thin vasvular wall. Some vessels, however, could be identified that had at first been regarded as arteries. A closer inspection, however, revealed the venous character of these muscularised vessels, which may correspond to the so called "Drosselvenen" described by Körner 50 years ago. These veins are supposed to possess a particular anatomical structure in their vascular wall called "sphincter", "muscular thickening", "cushion", or "muscular bolster" by various authors--which enables them to ease or to prevent the loss of fluid from the cavernous tissue. All our morphological findings as well as the functional significance of these peculiar structures are compared and discussed with the appropriate literature.

Responses of resistance and capacitance vessels in human nasal mucosa to beta-receptor agonists

To investigate the responses of nasal vessels, divided into resistance and capacitance vessels, to a beta-receptor agonist in human, mucosal blood flow of the inferior turbinate and nasal airway resistance were measured when 1.5 mg terbutaline was applied topically. Mucosal blood flow was measured by the hydrogen clearance method just beneath the site where terbutaline in physiological saline (0.02 ml) was applied on an extremely localized area of the nasal mucosa. Nasal airway resistance of the ipsilateral and contralateral nasal cavities was measured separately by anterior rhinomanometry when terbutaline in normal saline (0.1 ml) was sprayed in the unilateral nasal cavity. Topical application of terbutaline elicited neither a significant increase of mucosal blood flow of the inferior turbinate nor an increase of nasal airway resistance. beta-Receptors seem not to be as densely distributed both in the resistance vessels and in the capacitance vessels as to cause vasodilatation by their activation in the nasal mucosa.

Human nasal blood vessels after permanent tracheostomy. Electron-microscopic study

Biopsy specimens from the inferior turbimate of 13 permanently tracheostomized patients were examined by the electron microscope. Variations from the normal were recorded, as proliferation of capillaries, venous congestion and arteriolar contraction. The relation of shunting air away to these changes is discussed.

Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu disease). An electron microscopic study of the vascular lesions before and after therapy with hormones

Eight patients with hereditary hemorrhagic telangiectasia and severe epistaxis were treated with norethynodrel with mestranol (Enovid). Biopsy specimens of typical lesions from two patients were taken for electron microscopy before and after several months of therapy. Characteristic endothelial cell damage and nectosis were noted in the dilated venules of patients before treatment but not after. Unlined channels of blood were found in connective tissue before treatment but not after. These are thought to arise from leaks in the affected venules, and it is suggested that later indothelial ingrowth gives rise to the propagation of lesions that are known to develop with age. Reduplicated basal laminae and regenerating endothelial cells were found both before and after treatment.

Sympathetic stimulation and otic blood flow

The radioactive microsphere technique was used in dogs to assess the effect of sympathetic stimulation on temporal bone blood flow. The stellate, caudal cervical and superior cervical ganglia, and the vertebral and cervical sympathetic nerves were stimulated. In a large majority of the animals, stimulation had no effect on temporal bone blood flow although nasal tissue was greatly affected. In a minority of animals, a small effect was seen in temporal bone tissue. Similarly, norepinephrine infusion usually did not produce evidence of reduced blood flow in the temporal bone. It was concluded that the sympathetic innervation of otic blood vessels was not capable of controlling otic blood flow, only modulating it. A sympathetic vasospasm does not seem possible. Mention is made of the dual sympathetic innervation of the cochlea described by Spoendlin and Ross. The possible mediation of sympathetic effects in the cochlea by cyclic AMP is suggested.

Blood flow in otorhinologic tissue after histamine and papaverine

A method has evolved that allows one to quantitatively measure nutritional blood flow in the labyrinth. Several otic symptoms (e.g., sudden hearing loss) are thought to be due to decreased labyrinthine blood flow. Our aim was to test two common vasodilators, histamine and papaverine, to determine if they were effective in increasing blood flow to otic tissue. The method employs the intracardiac injection of radioactive microspheres (15 μ in diameter). These spheres become embolized in the microcirculation and provide a measure of blood flow in ml/gm/min. Histamine or papaverine were infused intravenously for five min at several doses. Blood flow was measured before and after infusion. Both drugs cause a significant increase in blood flow to temporal bone tissue if used in the appropriate dose range, i.e., about 1 ug/kg/min for histamine and 0.5 mg/kg/min for papaverine. If the dose of either drug is increased to the point that causes a drop of more than 15 mm Hg in systemic blood pressure, there is either no increase or a drop in otic blood flow. This reversal of the drug response is felt to be due to autoregulatory mechanisms in intracranial blood vessels.