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PubMed2002

Velopharyngeal surgery: a prospective randomized study of pharyngeal flaps and sphincter pharyngoplasties.

Residual velopharyngeal insufficiency after palatal repair varies from 10 to 20 percent in most centers. Secondary velopharyngeal surgery to correct residual velopharyngeal insufficiency in patients with cleft palate is a topic frequently discussed in the medical literature. Several authors have reported that varying the operative approach according to the findings of videonasopharyngoscopy and multiview videofluoroscopy significantly improved the success of velopharyngeal surgery. This article compares two surgical techniques for correcting residual velopharyngeal insufficiency, namely pharyngeal flap and sphincter pharyngoplasty. Both techniques were carefully planned according to the findings of videonasopharyngoscopy and multiview videofluoroscopy. Fifty patients with cleft palate and residual velopharyngeal insufficiency were randomly divided into two groups: 25 in group 1 and 25 in group 2. Patients in group 1 were operated on by using a customized pharyngeal flap according to the findings of videonasopharyngoscopy and multiview videofluoroscopy in each case. Those in group 2 received a sphincter pharyngoplasty also customized according to the findings of videonasopharyngoscopy and multiview videofluoroscopy. The median age of the patients in both groups was not significantly different (p > 0.5). The frequency of residual velopharyngeal insufficiency after the individualized velopharyngeal surgery was not significantly different between the patient groups (12 percent versus 16 percent; p > 0.05). It seems that customized pharyngeal flaps and sphincter pharyngoplasties performed according to the findings of videonasopharyngoscopy and multiview videofluoroscopy are safe and reliable procedures for treating residual velopharyngeal insufficiency in cleft palate patients.

Child↗

PubMed2003

Fgfr1 regulates patterning of the pharyngeal region.

Development of the pharyngeal region depends on the interaction and integration of different cell populations, including surface ectoderm, foregut endoderm, paraxial mesoderm, and neural crest. Mice homozygous for a hypomorphic allele of Fgfr1 have craniofacial defects, some of which appeared to result from a failure in the early development of the second branchial arch. A stream of neural crest cells was found to originate from the rhombomere 4 region and migrate toward the second branchial arch in the mutants. Neural crest cells mostly failed to enter the second arch, however, but accumulated in a region proximal to it. Both rescue of the hypomorphic Fgfr1 allele and inactivation of a conditional Fgfr1 allele specifically in neural crest cells indicated that Fgfr1 regulates the entry of neural crest cells into the second branchial arch non-cell-autonomously. Gene expression in the pharyngeal ectoderm overlying the developing second branchial arch was affected in the hypomorphic Fgfr1 mutants at a stage prior to neural crest entry. Our results indicate that Fgfr1 patterns the pharyngeal region to create a permissive environment for neural crest cell migration.

Alleles↗

PubMed1998

Attachment of nontypable Haemophilus influenzae to human pharyngeal epithelial cells mediated by a ganglioside receptor.

Nontypable Haemophilus influenzae (NTHI) is one of the major pathogens of human respiratory infections and has the ability to attach to pharyngeal epithelial cells. We characterized the epithelial cell receptor to which NTHI bind. Neuraminidase pretreatment of pharyngeal epithelial cells resulted in a significant decrease in NTHI attachment, suggesting sialic acid as an important component of the receptor. The attachment was not decreased in NTHI pretreated with 1,000 microg/ml of fucose, N-acetyl-neuraminic acid, N-acetyl-glucosamine, N-acetyl-galactosamine, acetyl-salicylic acid and colominic acid. Only treatment with gangliosides D1a, D1b and D2 at a concentration of 12.5 microg/ml significantly decreased the attachment. On the other hand, treatment with gangliosides M1, M2, M3, D3, T1b and asialoganglioside M1 did not decrease the attachment of NTHI. Only ganglioside D2 inhibited the attachment significantly at a concentration of 12.5 ng/ml. Other isolates of NTHI showed a decrease in attachment after treatment with ganglioside D2. Treatment of cells with anti-human GD2 monoclonal antibody also decreased the attachment of NTHI in a dose-dependent manner. This study indicates that sialic acid glycoconjugate, GD2, is one of the receptors of NTHI on human pharyngeal epithelial cells.

Antibodies, Monoclonal↗

PubMed2006

Evaluation of topical pharyngeal anaesthesia by benzocaine lozenge for upper endoscopy.

BACKGROUND: Among the randomized controlled trials evaluating the effect of pharyngeal anaesthesia only some suggest benefit. Spray is irritating for some people and leaves bitter taste in the throat. We hypothesized that delivering the local anaesthetic as a sucking lozenge would benefit the patients in terms of decreasing anxiety and will improve procedure performance and patient tolerance. AIM: To determine whether benzocaine/tyrothricin sucking lozenges with conscious sedation is superior to conscious sedation alone, with respect to procedure performance and tolerance in patients undergoing upper endoscopy. METHODS: One hundred and seventy-four adult patients undergoing upper endoscopy with conscious sedation completed the study. They were randomized to receive sucking lozenge containing benzocaine or placebo before the procedure. Patients were asked to rate prestudy anxiety, tolerance for topical pharyngeal anaesthesia, comfort during endoscopy, degree of difficulty of intubation, postprocedure throat discomfort and willingness to undergo subsequent examinations using a 10-cm visual analogue scale. Endoscopists were asked to estimate the ease of oesophageal intubation and procedure performance. RESULTS: No significant statistical differences regarding all the points studied were found between the groups. CONCLUSIONS: Topical pharyngeal anaesthesia with benzocaine/tyrothricin lozenges with conscious sedation has no advantages over conscious sedation alone in patients undergoing upper endoscopy.

Administration, Topical↗

PubMed1993

Throat pain and pharyngeal packing: a controlled randomized double-blind comparison between gauze and tampons.

In order to determine whether patients having pharyngeal packing experience more or less post-operative throat pain when tampons were used, 80 patients were randomized into two groups to receive either gauze or tampon pharyngeal packing. A third control group of 40 patients were intubated but did not have any throat packs. Post-operative throat pain was subjectively rated at both 6 hours and at 24 hours by an independent observer. Thirty-eight per cent of patients had moderate or severe throat pain in the gauze group, whilst in the tampon and control groups these amounted to only 15% and 1% respectively. A significantly higher proportion of patients also had a moderate or severe sore throat at 24 hours in the former group. Intubation alone resulted in a sore throat post-operatively in 50% of patients, but 85% of those had a mild sore throat only. No differences in pain ratings in any group could be shown between men or women or between age groupings. Endotracheal intubation often causes post-operative throat pain which is exacerbated by the use of pharyngeal packing. The results presented suggest that tampons are a safe, effective alternative to gauze and result in less severe post-operative throat pain.

Double-Blind Method↗

PubMed2005

Pharyngeal and laryngeal symptoms and signs related to extraesophageal reflux in patients with heartburn in gastroenterology practice: a prospective study.

OBJECTIVES: To describe pharyngeal and laryngeal symptoms and findings in correlation to extraesophageal reflux (EER) in patients with heartburn. DESIGN: A prospective study. SETTING: Patients referred to Department of Gastroenterology, Karolinska University Hospital Huddinge. PARTICIPANTS: Forty-three patients with chronic heartburn as the primary symptom, subdivided on the basis of oesophageal manometry to have gastro-oesophageal reflux disease (GORD) (n = 25) or not (n = 18). MAIN OUTCOME MEASURES: Laryngeal video recordings of 43 patients were examined off-line. The occurrence of symptoms and laryngeal pathology were correlated to the results of 24-h double-probe pH monitoring. RESULTS: Pharyngeal or laryngeal symptoms occurred often or quite often in 72% (18 of 25) of the GORD patients and 61% (11 of 18) of the patients without GORD. EER occurred in 73% (16 of 22) of the GORD patients with laryngeal symptoms and in 38% (6 of 16) of those without GORD but with laryngeal symptoms (P = 0.047). In the multivariate analysis the odds for hoarseness was 17 times higher if the patient had heartburn more than five times a day, compared with patients with heartburn less than once a day (OR 17.8, CI 1.7-405.9; P = 0.01). Cohen's kappa for intrarater reliability was 0.851 (P = 0.001). Laryngeal pathology was found in 56% of the GORD patients and 44% patients without GORD. There was no significant difference in the occurrence of any specific symptom or finding between the patients with and without GORD, nor with and without EER. CONCLUSIONS: Although GORD together with laryngeal symptoms seem to be predictive of EER, there are no specific pharyngeal and laryngeal symptoms or findings that would help distinguishing patients with EER from those without. However, the more frequent the heartburn to the more frequent is hoarseness.

Adult↗

PubMed2006

Histology and histochemistry of the pharyngeal cavity and oesophagus of the silverside Odontesthes bonariensis (Cuvier and Valenciennes).

The histology of the pharyngeal cavity and oesophagus of the freshwater 'silverside'Odontesthes bonariensis (Cuvier and Valenciennes) and the characteristics of their mucous cells were investigated. The histological characterization of its digestive wall revealed that the mucosa is thrown with longitudinal folds. The epithelium covering the folds was stratified with abundant mucous cells and gustative corpuscles, which are lacking in the oesophagus. The muscularis mucosa was absent. The submucosa presented the compactum stratum. The muscularis was organized in longitudinal and circular layers of muscular striated fibres. The serosa with a flat epithelium was located only in the oesophagus. Using histochemical procedures including methods for localization and characterization of glycoproteins (GPs), no differences were detected between the mucous cells contents of the pharyngeal cavity and those of the oesophagus. The mucous cells showed a weak periodic acid-Schiff (PAS) positive reaction in their content. The reactions for the differential analysis of sialic acids from GPs are feeble for periodic acid-Schiff at low temperature and low pH (PA*S) and KOH/PA*S and strong for periodic acid/borohydride/KOH/PAS (PA/Bh/KOH/PAS) and KOH/PA*/Bh/PAS revealing the scarce presence of C7 or C9 substituted and non-substituted sialic acids and the abundance of C7, C8 substituted sialic acids, O-acyl sugars and neutral sugars respectively. The results suggest that the pharyngeal cavity with the gustative corpuscles would induce the gastric secretion whereas the oesophagus is mainly involved in the transport of the food bolus to the stomach with the aid of abundant secretion of mucus. GPs secreted on the surface of the mucous cells, likely related to environmental conditions, would be involved in the lubrication, protection against abrasion and inhibition of microorganism proliferation.

Animals↗

PubMed1999

Effect of co-activation of tongue protrudor and retractor muscles on tongue movements and pharyngeal airflow mechanics in the rat.

1. The purpose of these experiments was to examine the mechanisms by which either co-activation or independent activation of tongue protrudor and retractor muscles influence upper airway flow mechanics. We studied the influence of selective hypoglossal (XIIth) nerve stimulation on tongue movements and flow mechanics in anaesthetized rats that were prepared with an isolated upper airway. In this preparation, both nasal and oral flow pathways are available. 2. Inspiratory flow limitation was achieved by rapidly lowering hypopharyngeal pressure (Php) with a vacuum pump, and the maximal rate of flow (VI,max) and the nasopharyngeal pressure associated with flow limitation (Pcrit) were measured. These experimental trials were repeated while nerve branches innervating tongue protrudor (genioglossus; medial XIIth nerve branch) and retractor (hyoglossus and styloglossus; lateral XIIth nerve branch) muscles were stimulated either simultaneously or independently at frequencies ranging from 20-100 Hz. Co-activating the protrudor and retractor muscles produced tongue retraction, whereas independently activating the genioglossus resulted in tongue protrusion. 3. Co-activation of tongue protrudor and retractor muscles increased VI, max (peak increase 44 %, P < 0.05), made Pcrit more negative (peak decrease of 44 %, P < 0.05), and did not change upstream nasopharyngeal resistance (Rn). Independent protrudor muscle stimulation increased VI,max (peak increase 61 %, P < 0.05), did not change Pcrit, and decreased Rn (peak decrease of 41 %, P < 0.05). Independent retractor muscle stimulation did not significantly alter flow mechanics. Changes in Pcrit and VI,max at all stimulation frequencies were significantly correlated during co-activation of protrudor and retractor muscles (r2 = 0.63, P < 0.05), but not during independent protrudor muscle stimulation (r2 = 0.09). 4. These findings indicate that either co-activation of protrudor and retractor muscles or independent activation of protrudor muscles can improve upper airway flow mechanics, although the underlying mechanisms are different. We suggest that co-activation decreases pharyngeal collapsibility but does not dilate the pharyngeal airway. In contrast, unopposed tongue protrusion dilates the oropharynx, but has a minimal effect on pharyngeal airway collapsibility.

Animals↗

PubMed1996

Attachment of Moraxella catarrhalis to pharyngeal epithelial cells is mediated by a glycosphingolipid receptor.

Moraxella catarrhalis is one of the major pathogens of respiratory infections and has the ability to attach to the pharyngeal cells iva fimbriae. We characterized the epithelial cell receptor to which fimbriate M. catarrhalis binds. Neuraminidase pretreatment of pharyngeal epithelial cells resulted in a significant decrease of M. catarrhalis attachment, suggesting interaction with the sialic acid component. The attachment was not decreased in M. catarrhalis pretreated with 2 and 1 mg/ml of fucose, N-acetyl-neuraminic acid, N-acetyl-glucosamine, N-acetyl-galactosamine, acetyl-salicylic acid and colominic acid. However, M. catarrhalis treated with gangliosides M1, M2, D1a, D1b and T1a at a concentration of 2.5 micrograms/ml had significantly decreased the attachment compared to the control. In contrast treatment with gangliosides M3 and asialoganglioside M1 did not decrease the attachment of M. catarrhalis and thereby provided evidence for specificity of the inhibition. Concentration dependent effects of ganglioside M2 on the attachment were also observed. Other fimbriate isolates of M. catarrhalis showed decrease in attachment after treatment with ganglioside M2. However there was no effect on attachment when a nonfimbriate isolate was treated with ganglioside M2. This study indicates that the receptor of fimbriate M. catarrhalis on pharyngeal epithelial cells resides in the sequences of ganglioside M2.

Bacterial Adhesion↗

PubMed1995

Positioning improves the oral and pharyngeal swallowing function in children with cerebral palsy.

Many children with cerebral palsy have feeding difficulties. The aim of this study was to investigate if trunk and neck positioning influenced oral and pharyngeal swallow. Five children with feeding problem aged 3-10 years with cerebral palsy were examined using videofluoroscopy. All children had tetraplegia with dystonia, i.e. poor head control and poor trunk stability. All children had gross aspiration and posterior oral leak. The pharyngeal phase was delayed in relation to the oral phase. Two children had pharyngeal retention. The children were positioned with both an extended and flexed neck. The flexed neck position was combined with a 30 degrees reclined sitting position. In both positions they were given purée with barium and liquid barium during video recording. In the reclined position with the neck flexed, aspiration decreased in all five children, oral leak diminished in two children and retention improved in one child.

Cerebral Palsy↗

PubMed1994

Reflex recruitment of medullary gasping mechanisms in eupnoea by pharyngeal stimulation in cats.

1. Mechanical stimulation of the naso- and oropharynx causes the replacement of the eupnoeic ventilatory pattern by a brief, but large, burst of activity of the phrenic nerve. Our purpose was to define whether these changes in phrenic activity represent a switch to gasping. 2. In decerebrate, vagotomized, paralysed and ventilated cats, mechanical stimulation of the pharynx was performed during eupnoea, apneusis and gasping. The latter two ventilatory patterns were produced by ventilating the experimental animal with 1.0% carbon monoxide in air or with 100% nitrogen. Eupnoea could be re-established by a recommencement of ventilation with oxygen. 3. The rate of rise of phrenic activity and its peak height were much greater following mechanical stimulation of the pharynx than the phrenic bursts of eupnoea or apneusis. The durations of phrenic burst and the period between these were much less following pharyngeal stimulation. In contrast, these variables of phrenic activity were the same during pharyngeal stimulation and in gasping. 4. Previous studies had established that activity within a region of the lateral tegmental field of medulla is critical for the manifestation of gasping. Hence, electrical stimulation of this region during gasping elicits premature gasps whereas its ablation irreversibly eliminates gasping. 5. We positioned a multibarrelled pipette in the critical medullary region for gasping. Its location was verified, once gasping was established in hypoxia or anoxia, by the elicitation of premature gasps following electrical stimulation. Neurons in this region were destroyed by microinjections of the neurotoxin kainic acid; in a few experiments the region was destroyed by electrolytic lesions. 6. Following destruction of the region of the lateral tegmental field, gasping could no longer be provoked in anoxia. In contrast, the eupnoeic pattern of phrenic activity continued. However, mechanical stimulation of the pharynx no longer caused any changes in the on-going pattern of phrenic activity. 7. We conclude that mechanical stimulation of the pharynx elicits a powerful reflex by which eupnoea is suppressed and gasping is elicited. Stated differently, the changes in phrenic activity during this pharyngeal stimulation in fact represent gasps. 8. Gasps are dependent upon activity within a region of the lateral tegmental field of the medulla. This region plays no role in the neurogenesis of eupnoea. Hence, our results provide additional support for the concept that there are multiple sites for ventilatory neurogenesis in the mammalian brainstem.

Animals↗

PubMed1986

Superior lateral pharyngeal wall movements in speech.

Medial movements of the lateral pharyngeal wall at the level of the velopharyngeal port were examined by using a computerized ultrasound system. Subjects produced CVNVC sequences involving all combinations of the vowels /a/ and /u/ and the nasal consonants /n/ and /m/. The effects of both vowels on the CVN and NVC gestures (opening and closing of the velopharyngeal port, respectively) were assessed in terms of movement amplitude, duration, and movement onset time. The amplitude of both opening and closing gestures of the lateral pharyngeal wall was less in the context of the vowel /u/ than the vowel /a/. In addition, the onset of the opening gesture towards the nasal consonant was related to the identity of both the initial and the final vowels. The characteristics of the functional coupling of the velum and lateral pharyngeal wall in speech are discussed.

Adult↗

PubMed2004

Reemergence of macrolide resistance in pharyngeal isolates of group a streptococci in southwestern Pennsylvania.

We previously reported on the emergence of macrolide-resistant pharyngeal isolates of group A streptococci (GAS) in our community. The purpose of the present study was to track longitudinal trends in macrolide resistance in these isolates in southwestern Pennsylvania. Testing for susceptibility to erythromycin and clindamycin was performed for all pharyngeal GAS isolates recovered at the Children's Hospital of Pittsburgh and a local pediatric practice between September 2001 and May 2002. Macrolide resistance phenotypes and genotypes were determined by double-disk diffusion and PCR, respectively. Strain relatedness was determined by field inversion gel electrophoresis and emm gene sequence typing. A total of 708 isolates of GAS were recovered during the study period; 68 (9.6%) were macrolide resistant, while all isolates were sensitive to clindamycin. The monthly prevalence of macrolide resistance ranged from 0 to 41%. Only 21 of 573 (3.7%) strains recovered from September 2001 through March 2002 were macrolide resistant. A sudden increase in the rate of macrolide resistance (47 of 135 isolates [35%]) was seen in April and May 2002. Sixty-two isolates demonstrated the M phenotype (resistance to macrolide antibiotics), and six isolates demonstrated the MLS(B) phenotype (resistance to most macrolide, lincosamide, and streptogramin B antibiotics); these isolates were confirmed to be mef(A) and erm(A), respectively. Three unique mef(A) clones and four unique erm(A) clones were identified among the resistant isolates. The MIC at which 50% of isolates are inhibited (MIC(50)) for the mef(A) strains was 16 micro g/ml, while the MIC(50) for erm(A) strains was 8 micro g/ml. The finding of high levels of macrolide resistance among pharyngeal isolates of GAS for a second successive year in our community raises the concern that this problem may be more common in the United States than was previously appreciated. Longitudinal surveillance of isolates from multiple centers is needed to define the prevalence of antimicrobial agent-resistant GAS in the United States.

Anti-Bacterial Agents↗

PubMed1979

Bacterial adherence to pharyngeal cells in smokers, nonsmokers, and chronic bronchitics.

Selective adherence to host mucosal surfaces is probably a requirement for colonization and infection by bacteria. Since pharyngeal colonization may be an important determinant in the pathogenesis of pneumonia, we studied the adherence of 10 different bacteria to pharyngeal cells obtained from nonsmokers, smokers, and chronic bronchitics. Various patterns of adherence among the different groups of subjects were found. Young healthy smokers had increased adherence of Streptococcus pneumoniae type I and, to a lesser extent, S. pneumoniae type III and Staphylococcus aureus when compared with nonsmokers. Middle-aged smokers with a long history of chronic bronchitis had significantly increased adherence only of untypable Haemophilus influenzae when compared with age-matched nonsmokers. The acquisition of pneumococcal pneumonia by smokers and the role of nontypable Haemophilus species in chronic bronchitis may be determined, in part, by bacterial adherence to pharyngeal cells.

Adult↗

PubMed1993

Role of M protein in pharyngeal colonization by group A streptococci in rats.

As the initial step in infection, group A streptococci (GAS) colonize either the nasopharyngeal mucosa or the skin of humans. A number of virulence factors have been implicated in the colonization phase of pathogenesis based upon their in vitro activities, but the in vivo data supporting their role in colonization of the host tissues is lacking. In this investigation, the potential requirement for M protein in pharyngeal colonization by GAS was explored by using near-isogenic strains in experimental animals studies. Fischer rats were infected by intranasal and oral inoculation with both M-positive and M-negative Streptococcus pyogenes strains. Colonization of the pharyngeal area by the streptococci was monitored at various time intervals. Both M-positive and M-negative strains colonized during the first week following infection, indicating that M protein was not necessary for this initial colonization. Two M-positive strains of S. pyogenes were recovered from the rats up to 23 weeks following inoculation, while the colonization levels for M-negative strains decreased rapidly in the second and third weeks, becoming negligible by the fourth week. This indicates a potential role for M protein in the persistence of colonization at this mucosal surface. Colonization of rats with either M-positive strain of S. pyogenes also resulted in the appearance of salivary and serum antibody responses. This in vivo model should allow further investigation into factors required for GAS disease, including the examination of the potential role of the host immune response both in modulation of the pharyngeal surface and in modulation of antigenic changes in M protein or other surface factors.

Adhesins, Bacterial↗

PubMed2002

Pharyngeal branch of the glossopharyngeal nerve plays a major role in reflex swallowing from the pharynx.

Mechanical stimulation of the pharyngeal areas readily elicits reflex swallowing. However, it is much more difficult for electrical stimulation of the glossopharyngeal nerve (GPN) to evoke reflex swallowing than it is for stimulation of the superior laryngeal nerve (SLN) to do so. These paradoxical findings remain unexplained; hence, the main purpose of this study was to explain this contradiction by using a urethane-anesthetized rat. Mechanical stimulation easily elicited reflex swallowing from the pharynx. The posterior pillars, posterior pharyngeal wall, and the soft palate of the rat were extremely reflexogenic areas for swallowing. Sectioning the pharyngeal branch of the GPN (GPN-ph), however, eliminated the swallowing reflex from these areas. In contrast, sectioning the lingual branch of the GPN had no effect on the elicitation of swallowing. Electrical stimulation of the GPN-ph and SLN elicited sequentially occurring swallows. The relationship between stimulus frequency and the latency of swallowing for the GPN-ph was approximately the same as that for the SLN. These results indicate that the GPN-ph plays a major role in the initiation of reflex swallowing from the pharynx in rats.

Animals↗

PubMed1992

Effects of pharyngeal lubrication on the opening of obstructed upper airway.

We examined the effect of electrical stimulation of the hypoglossal nerve and pharyngeal lubrication with artificial surfactant (Surfactant T-A) on the opening of obstructed upper airway in nine anesthetized supine dogs. The upper airway was isolated from the lower airway by transecting the cervical trachea. Upper airway obstruction was induced by applying constant negative pressures (5, 10, 20, and 30 cmH2O) on the rostral cut end of the trachea. Peripheral cut ends of the hypoglossal nerves were electrically stimulated by square-wave pulses at various frequencies from 10 to 30 Hz (0.2-ms duration, 5-7 V), and the critical stimulating frequency necessary for opening the obstructed upper airway was measured at each driving pressure before and after pharyngeal lubrication with artificial surfactant. The critical stimulation frequency for upper airway opening significantly increased as upper airway pressure became more negative and significantly decreased with lubrication of the upper airway. These findings suggest that greater muscle tone of the genioglossus is needed to open the occluded upper airway with larger negative intraluminal pressure and that lubrication of the pharyngeal mucosa with artificial surfactant facilitates reopening of the upper airway.

Airway Obstruction↗

PubMed1993

Development of the pharyngeal arch system related to the pulmonary and bronchial vessels in the avian embryo. With a concept on systemic-pulmonary collateral artery formation.

BACKGROUND: The literature is ambiguous as to the question of the developmental background of systemic-pulmonary collateral arteries. These are found in combination with various congenital heart malformations such as pulmonary atresia. From a clinical point of view, it is of interest to know whether we are dealing with the persistence of transient embryological vessels such as ventral segmental arteries or parts of pharyngeal arch arteries or with the prenatal or postnatal recruitment of the bronchial vasculature that normally supplies the lung. This study of the embryology of the extrapulmonary and intrapulmonary vasculature aims at a better understanding of the variations in origin, course, branching pattern, and histology of collateral arteries. METHODS AND RESULTS: Serial sections of quail embryos ranging between stage HH11 and stage HH28 were incubated with a monoclonal antibody (alpha MB1) against endothelial cells and their precursors. Additional series of chick embryos were injected with india ink to study the lumenized vascular patterns. A splanchnic plexus consisting of endothelial cells and precursors is present around the foregut before the lung buds develop. This plexus expands and gives rise to the pharyngeal arch arteries, the ventral pharyngeal veins, the pulmonary vessels, and the bronchial vessels, including the intrapulmonary vessel network. During two subsequent periods, the splanchnic plexus is transiently connected to the systemic arteries and veins. The bronchial arteries and veins develop in the second period from these transient vessels. The expansion and extension of the splanchnic plexus to many organs during the formation of the bronchial vessels explains the varying course and branching pattern of the bronchial vasculature. CONCLUSIONS: These results show that we are not dealing with two or more individual vascular systems that contribute to the developing vessels of the lungs but with one vascular plexus that normally gives rise to the pulmonary and bronchial vasculature but has the potential to give rise to other systemic-pulmonary connections.

Animals↗