Posterior Pharynx Research Articles

Mandibular distraction osteogenesis in very young patients to correct airway obstruction.

The purpose of this study was to measure changes in the airway cross-sectional area of pediatric patients with micrognathia and obstructive airway symptoms after treatment by mandibular distraction. The measurements obtained were correlated with the clinical outcomes.Ten patients, ranging in age from 3 months to 8 years, underwent measurement and distraction. Eight patients were under 30 months of age. Six were diagnosed with Pierre Robin sequence, two with Treacher Collins syndrome, and two with Nager syndrome. All patients had retrognathia of greater than 8 mm and obstructive airway symptoms while awake that had resulted in tracheostomy (3), repeated apnea monitor triggering (5), or abnormal sleep study (2). Cephalometric analysis was performed pretreatment and posttreatment by distraction. The effective airway space was defined with the following boundaries: a horizontal line from the tip of the odontoid to the velum, the uvula tip to the tongue base along the shortest line, the tongue base down to the base of the epiglottis, and the horizontal line to the posterior pharynx. These lines were traced for each cephalogram, the outline was digitized, and the area was calculated by computer. An analysis of the square area change was done by paired t test. The range of distraction was 8 to 22 mm; the mean effective airway increase was 67.5 percent, with a range of 26 to 120 percent. Measurable airway increase occurred in all patients who underwent distraction, and all patients showed clinical improvement. Six patients with Pierre Robin sequence became asymptomatic, with normal sleep, feeding, and weight gain. Two patients with Nager syndrome and tracheostomies were decannulated and were asymptomatic postdistraction. One patient with Treacher Collins syndrome without tracheostomy became asymptomatic after mandibular distraction; one patient failed to distract because of premature consolidation and continued to require a cannula. Mandibular distraction seems to provide a consistent change in tongue base position that improves obstructive airway symptoms by increasing measured effective airway space. The potential for mandibular distraction exceeds the simple correction of malocclusion also by eliminating soft-tissue obstruction of the micrognathic airway. Airway improvement is independent of the syndrome diagnosed. Mandibular distraction osteogenesis may be useful to avoid or decannulate existing tracheostomy in infants with micrognathia.

A New Species of Nematodes Found in Rotting Seaweed on the Shore of the Black Sea

A new species of nematodes, Pellioditis obesasp. n., found in rotting seaweed in the supralittoral area of the Black Sea near Sevastopol (Ukraine) is described and illustrated. The new species is morphologically similar to P. ehrenbaumi(Bresslau and Sch. Stekhoven, 1935); but it differs in having a narrow protostoma cylinder, a shorter female tail, larger eggs, longer spicules and gubernaculum, and in the ratio of the anterior pharynx length to the posterior pharynx length.

Glossoptosis (posterior displacement of the tongue) during sleep: a frequent cause of sleep apnea in pediatric patients referred for dynamic sleep fluoroscopy.

The purpose of this study was to evaluate the frequency of glossoptosis (posterior displacement of the tongue) as a cause of sleep apnea in pediatric patients referred for fluoroscopic sleep studies. Seventy consecutive dynamic fluoroscopic sleep studies performed to evaluate sleep apnea were reviewed. All patients had been sedated and examined with lateral fluoroscopy during sleep. Anatomic changes in the airway were correlated with episodes of oxygen desaturation. Cases of glossoptosis, in which the tongue moved posteriorly during sleep and abutted the posterior pharynx, resulting in airway obstruction and oxygen desaturation, were identified. Associated factors were reviewed. Of 70 sleep studies reviewed, glossoptosis was the cause of airway obstruction in 17 patients (24%). Mean age in these 17 patients was 3 years (range, 5 days to 13 years). Seven of the 17 children were younger than 1 year old. Only three patients had no underlying medical problems. Four patients had macroglossia (Down syndrome, n = 3; duplicated tongue, n = 1) as a cause, and three patients had micro- or retrognathia (Pierre Robin syndrome, n = 2; Rubinstein-Taybi syndrome, n =1) as a cause. Six patients had neuromuscular abnormalities. Glossoptosis was a cause of airway obstruction in 25% of pediatric patients referred for fluoroscopic sleep studies. Attention to this anatomic region is important when evaluating children with sleep apnea.

Mucosal pressure and oropharyngeal leak pressure with the ProSeal versus laryngeal mask airway in anaesthetized paralysed patients

The ProSeal laryngeal mask airway (PLMA) is a new laryngeal mask device with a larger, wedge-shaped cuff and a drainage tube. We tested the hypothesis that directly measured mucosal pressure and oropharyngeal leak pressure (OLP) are higher for the PLMA compared with the laryngeal mask airway (LMA). We also assess the mechanism of seal, and the reliability of cuff volume, in vivo intracuff pressure and calculated mucosal pressure (in vivo minus in vitro intracuff pressure) to predict directly measured mucosal pressure. Thirty-two anaesthetized, paralysed adult patients were randomly allocated to receive either a size 4 LMA or PLMA. Microchip sensors were attached at locations corresponding to: (a) base of tongue; (b) distal oropharynx; (c) hypopharynx; (d) lateral pharynx; (e) posterior pharynx; and (f) pyriform fossa. In vitro and in vivo intracuff pressures, OLP and directly measured mucosal pressure were documented at zero volume and after each 10 ml up to 40 ml. Directly measured mucosal pressure was similar between devices for a given cuff volume, but was lower for the PLMA for a given OLP. Directly measured mucosal pressure was highest in the distal oropharynx for both devices, but rarely (< 5%) exceeded 35 cm H2O. OLP was higher for the PLMA at all cuff volumes. Directly measured mucosal pressure was usually lower than OLP for both devices, and there was a positive correlation between directly measured mucosal pressure and OLP. Cuff volume, in vivo intracuff pressure and calculated mucosal pressure were poor to moderate predictors of directly measured mucosal pressure for the LMA and PLMA. We conclude that the PLMA forms a better seal than the LMA without an increase in directly measured mucosal pressure.

Mucosal swabs detect HPV in laryngeal papillomatosis patients but not family members

Seven patients, aged 2–7 years, with active recurrent respiratory papillomatosis (RRP) attending the University of Michigan Pediatric Otolaryngology Clinic were studied to determine if human papillomavirus (HPV) is harbored in sites of the upper aerodigestive tract other than in the laryngeal papilloma itself. We also determined if close family members had detectable virus in their oral cavities. Noninvasive swabs of buccal mucosa, posterior pharynx, nasal vestibule, and tonsillar pillar of patients, as well as buccal mucosa and posterior pharyngeal swabs of family members were studied. Swabs of the patients' papillomas served as the positive controls. HPV was detected using polymerase chain reaction (PCR) amplification and Southern hybridization techniques. Six of seven patients had detectable HPV in papilloma and endolaryngeal swabs. Four were HPV type 6, and two were HPV type 11. The patient whose swab was negative for HPV was found to be biopsy negative for papilloma 3 weeks after a single laser excision which was performed 6 months prior to the endolaryngeal swab. HPV types 16, 18 and 31 were not found in any of the patients. No swabs from other sites in patients or family members were HPV positive despite the presence of adequate DNA in the swabbed material for successful amplification of β-actin sequences. The absence of HPV (other than in the papilloma itself) in the upper aerodigestive tract of patients and caregivers is consistent with the absence of reported cases of horizontal transmission to siblings or other family members. The findings are also consistent with the conventional view that juvenile respiratory HPV is transmitted vertically from vaginal condylomas in the mother.

7144 “the bone in my throat belongs to me” : pharnygeal dysphagia from anterior cervical osteophytes.

69 yo male with a long-standing history of gastroesophageal reflux disease presented with a pressure sensation in his posterior pharynx. Dysphagia associated with this sensation resulted in a 20 lb weight loss and the inability to swallow his medications. Evaluation with a video endoscope revealed several large osteophytes in the midline of the posterior pharynx with an osteophyte from C-5 covering the proximal part of the upper esophageal sphincter. The obstruction of the upper esophageal sphincter was confirmed by a barium swallow and a MRI documented the location and benign nature of these phenomenally large anterior osteophytes. Anterior cervical osteophytectomy by our neurosurgeon (CFE) resulted in prompt, complete resolution of the globus sensation, the feeling of a bone in the posterior pharynx and the dysphagia. Conclusion: Anterior cervical osteophytes can cause pharyngeal dysphagia by physical obstruction of the proximal upper esophageal sphincter. Endoscopy, lateral neck films, barium swallow and MRI demonstrated the pathology which was readily reversed by surgery. 69 yo male with a long-standing history of gastroesophageal reflux disease presented with a pressure sensation in his posterior pharynx. Dysphagia associated with this sensation resulted in a 20 lb weight loss and the inability to swallow his medications. Evaluation with a video endoscope revealed several large osteophytes in the midline of the posterior pharynx with an osteophyte from C-5 covering the proximal part of the upper esophageal sphincter. The obstruction of the upper esophageal sphincter was confirmed by a barium swallow and a MRI documented the location and benign nature of these phenomenally large anterior osteophytes. Anterior cervical osteophytectomy by our neurosurgeon (CFE) resulted in prompt, complete resolution of the globus sensation, the feeling of a bone in the posterior pharynx and the dysphagia. Conclusion: Anterior cervical osteophytes can cause pharyngeal dysphagia by physical obstruction of the proximal upper esophageal sphincter. Endoscopy, lateral neck films, barium swallow and MRI demonstrated the pathology which was readily reversed by surgery.

Laryngeal Mask Airway Size Selection in Males and Females: Ease of Insertion, Oropharyngeal Leak Pressure, Pharyngeal Mucosal Pressures and Anatomical Position

We have compared ease of insertion, oropharyngeal leak pressure, directly measured pharyngeal mucosal pressure and anatomical position (assessed fibreoptically) for the size 4 and size 5 laryngeal mask airway (LMA) in 20 male and 20 female patients. Microchip pressure sensors were attached to the LMA at locations corresponding to the piriform fossa, hypopharynx, base of the tongue, lateral and posterior pharynx, and the oropharynx. Oropharyngeal leak pressure, mucosal pressure and fibreoptic position were recorded during inflation of the cuff from 0 to 30 ml in 10-ml increments. In males, oropharyngeal leak pressure over the inflation range was higher for size 5 (21 vs 17 cm H2O; P = 0.01); mucosal pressure over the inflation range was higher in the posterior pharynx for size 4 (7 vs 2 cm H2O; P = 0.007), and higher in the piriform fossa (8 vs 5 cm H2O; P = 0.003) and hypopharynx (9 vs 5 cm H2O; P = 0.003) for size 5. In females, oropharyngeal leak pressure over the inflation range was the same (21 vs 21 cm H2O), but mucosal pressure over the inflation range was higher in the piriform fossa (21 vs 8 cm H2O; P = 0.003) and posterior pharynx (4 vs 2 cm H2O; P = 0.004) for size 4, and higher in the lateral pharynx (5 vs 1 cm H2O; P = 0.01) and oropharynx (11 vs 5 cm H2O; P = 0.009) for size 5. The distribution of mucosal pressure was different for size 4 between males and females, but not for size 5. For both males and females, fibreoptic position was similar. We conclude that the size 5 LMA is optimal in males, but either size is suitable for females. The shape of the pharynx may be different between males and females.

Pediatric foreign body aspiration.

1. Joshua D. Rovin, MD* 2. Bradley M. Rodgers, MD† 1. 2. *Division of Pediatric Surgery, Children’s Medical Center, University of Virginia Health Sciences Center, Charlottesville, VA. 3. 4. †Editorial Board. After completing this article, readers should be able to: 1. Delineate the signs and symptoms of foreign body aspiration. 2. Explain the process of evaluating for suspected foreign body aspiration. 3. Describe the possible radiographic manifestations of foreign body aspiration. 4. Explain the management of foreign body aspiration in children. 5. Delineate the potential late complications of foreign body aspiration. Aspiration of foreign bodies by children can lead to serious illness and sometimes even death. According to National Safety Council statistics, in 1995, mechanical suffocation accounted for 5% (167) of all unintentional deaths among children in the United States younger than 4 years of age. Most of these deaths occurred in children younger than 1 year of age (81 deaths, accounting for 10% of all unintentional deaths in children younger than 1 year of age). Fortunately, the number of deaths has decreased over the past decade, which has been attributed to better education of the public and stricter guidelines for toy manufacturers. Nevertheless, foreign body aspiration continues to account for a significant number of preventable childhood deaths. Younger children are at the highest risk for accidental foreign body aspiration. This increased incidence has been attributed to several factors among younger children, including that they: 1) have the tendency to put small objects into their mouths; 2) often cry, shout, run, and play with objects in their mouths; and 3) do not have molars to chew certain foods adequately. Most studies show that fewer than 15% of foreign body aspirations occur among children older than 5 years of age. Boys comprise more than 50% of all cases of foreign body aspiration. By far, the objects aspirated most frequently are organic or food matter. In North America, peanuts are most common (Table 1⇓ ). View this table: Table 1. Commonly Aspirated Foreign Bodies Unlike aspiration in adults, there is only a …

Posterior fossa boost in medulloblastoma: an analysis of dose to surrounding structures using 3-dimensional (conformal) radiotherapy

Purpose: The purpose of this study was to compare three different techniques of delivering the posterior fossa boost in patients with medulloblastoma. Methods and Materials: Five patients underwent CT simulation for treatment planning of the posterior fossa boost. For each slice, the posterior fossa was contoured in addition to the cochlea, non–posterior fossa brain, pituitary gland, mandible, parotid glands, thyroid gland, pharynx, and cervical spinal cord. For each patient, plans for three techniques of delivering the posterior fossa boost were compared. Technique A utilized parallel-opposed lateral fields using bony landmarks (2-dimensional radiotherapy); the other two techniques were planned using 3-dimensional radiotherapy. Technique B utilized a pair of coplanar wedged posterior oblique beams, whereas Technique C utilized a pair of posterior oblique fields and a vertex field. Dose–volume histograms (DVH) were obtained for each of the organs contoured and for each technique and patient. The maximum, minimum, and mean dose to each organ were determined using the DVH program in our treatment planning system. Results: In 3 of 5 patients, the planning target volume (PTV) was not included in the treatment field with Technique A. The cochlea received 100%, 50%, and 42% of the prescribed posterior fossa dose using Techniques A, B, and C respectively. The mean dose to the non–posterior fossa brain was highest with Technique C, intermediate with Technique A, and lowest for Technique B. The mean dose to the non–posterior fossa brain with Technique B was comparable to the mean non–posterior fossa brain dose delivered using parallel-opposed lateral fields based on the CT definition of the PTV. Likewise, mean dose to the pituitary gland was lowest for Technique B. Both Techniques B and C were associated with a higher mean dose to the thyroid gland, mandible, parotid glands, and pharynx. Conclusions: The use of Technique B minimized the radiotherapy dose to the cochlea, pituitary gland, and non–posterior fossa brain. Contrary to what one may expect, conformal radiotherapy using Technique B did not deliver a higher dose to the non–posterior fossa brain over standard parallel-opposed lateral fields. Other advantages of conformal techniques B and C over 2-dimensional radiotherapy are the inclusion of the PTV in all patients and a lower mean dose to the pituitary gland. The main disadvantage of conformal Techniques B and C employed in our patients is a higher mean dose to the thyroid gland and other tissues in the neck.

Macroscopic anatomy of the auditory tube diverticulum (guttural pouch) in the thoroughbred equine--a silicon mold approach.

The characteristics of the equine auditory tube diverticulum (guttural pouches) were studied in detail by the naked eye and silicon mold method. First, we examined the anatomical relationship between the guttural pouches and their associated bones and muscles. Secondly, a silicon mold was fabricated to clarify the three-dimensional aspect of the guttural pouches, paying a special attention to the distribution of major arteries and nerves surrounding it. Thirdly, the volume of the silicon mold was measured by immersing it in water. The guttural pouches are a pair of pouches located dorso-posteriorly to the posterior pharynx. The pouches had a close contact rostrally with the Os sphenoidale, ventrally with the pharynx and the esophagus, and caudally with the Articulatio atlantoaxialis. The left and right guttural pouches had almost the same capacity in each horse. The A. carotis interna, cranial ganglia of cervical nerves and cervical Truncus sympathicus, as well as the N. vagus, N. glossopharyngeus, N. hypoglossus, and Radices spinales of the N. accessorius, were present in the mucosal crease extending from the roof of the guttural pouches towards the middle of the caudal wall. The N. facialis appeared from the Foramen stylomastoideum ran dorsocaudally along the lateral recess. The N. mandibularis appeared from the Foramen lacerum went over the muscular process of an ear bone, ran along the roof of the lateral recess and finally continued with the rostral side of the guttural pouches. Lymph nodes, scattered on the mucosal surface, appeared as tiny indentations with approximately millet seed size on the silicon surface. The capacity of guttural pouches in adult horses (472 +/- 12.4 cm3) was three-fold larger than that in foals (145 +/- 9.4 cm3).

Prenatal Orogastric Gene Delivery Results in Transduction of the Small Bowel in the Fetal Rabbit

Background: Gene therapy for meconium ileus, or other genetic diseases involving the gastrointestinal epithelium, may be possible with prenatal delivery of the CFTR gene to the gastrointestinal tract. Although minimally invasive techniques will probably be used for any future therapy of gastrointestinal disease, it is important to first test this strategy with a reliable animal model. Methods: The technique of orogastric fetal gene delivery was assessed using 7 pregnant rabbits (22 days’ gestation n = 1, 25 days’ gestation n = 4, 28 days’ gestation n = 2). Four fetuses from each litter were given an adenoviral vector carrying a marker gene by instilling it into the posterior pharynx with an animal feeding needle (1 × 10¹⁰ particles of ADV/RSV/LacZ suspended in 0.3 ml of saline), with the untreated fetuses serving as control animals. Results: There were no recoverable fetuses from the does that had surgery at 22 and 28 days (n = 3) due to maternal death (n = 2) and premature delivery (n = 1). Among the 4 does that underwent hysterotomy at 25 days of gestation, 1 underwent cesarean section 2 days after fetal gene delivery and 3 delivered at term, 5 (n = 1) or 6 (n = 2) days following gene delivery. Eleven of the 16 experimental pups and 7 untreated control animals were collected alive, and were sacrificed at delivery for study. Nine of the 11 experimental pups (82%) showed positive blue (LacZ+) nuclei in the small intestine by X-gal staining. No positive cells were found in 7/7 control animals. The presence of the reporter gene LacZ was confirmed in 8/11 (73%) virus-treated pups by PCR with 5/5 control animals negative for LacZ by PCR. Conclusions: There was significant maternal and fetal loss related to anesthetic and husbandry issues when surgery was performed at 22 or 28 days of gestation. Based on these preliminary results, we conclude that orogastric gene delivery in the rabbit fetus at 25 days’ gestation is an encouraging animal model to study fetal delivery to the gastrointestinal tract.

Intraoperative electromyographic assessment of recurrent laryngeal nerve stress and pharyngeal injury during anterior cervical spine surgery with Caspar instrumentation.

Recurrent laryngeal nerve (RLN) injury occurs after anterior cervical spine procedures. In this study the authors used intraoperative electromyographic (EMG) monitoring of the posterior pharynx as a surrogate for RLN function and monitored endotracheal tube (ET) cuff pressure to determine if there was an association between these variables and clinical outcome. Sixty patients in whom anterior cervical spine procedures were to be performed comprised the study population. After intubation, the ET cuff was adjusted to a just-seal volume and attached to a pressure monitor. A laryngeal surface electrode was placed in the posterior pharynx, and spontaneous EMG activity was monitored throughout the procedure. Cuff pressures and EMG activity were recorded during neck retraction and when EMG activity increased 20% above baseline. Patients were divided into two groups: those with sore throat/dysphonia and those without symptoms. Cuff pressures and EMG values were compared between groups, and the differences were correlated with clinical outcome. Hoarseness immediately after surgery was reported in 38% of patients whereas 15% exhibited severe symptoms. In symptomatic patients the period of intubation had been longer, and the ET cuff pressures had been elevated. In most patients EMG activity increased during insertion of the retractor and decreased after its removal. In these patients a greater number of episodes of elevated EMG activity during surgery were also noted. Two patients experienced prolonged hoarseness, and one required teflon injections of the vocal fold. This patient's EMG activity increased (15-18 times baseline) during surgery. In the few patients who were symptomatic with increased EMG activity, neither the timing nor direction of change could be associated with symptoms. Intubation time and elevated ET cuff pressure were the most important contributors to dysphonia and sore throat after anterior cervical spine surgery.

The Innervated Gracilis Musculocutaneous Flap for Total Tongue Reconstruction

A functional neotongue following total glossectomy requires both soft-tissue bulk and reconstruction of muscle function. We used innervated transverse gracilis musculocutaneous flaps to reconstruct total glossectomy defects in eight patients. The obturator nerve to the gracilis muscle was approximated to the hypoglossal nerve to reinnervate the gracilis muscle by using microsurgical technique. The cutaneous paddle of the gracilis flap easily supplies sufficient bulk to replace the total glossectomy defect. Follow-up of patients ranged from 3 to 47 months. All patients were able to resume oral feeding. Electromyographic studies performed on one patient showed reinnervation of the flap with active elevation of the posterior pharynx. Ultimately, seven patients died because of recurrence of their disease. The innervated gracilis musculocutaneous flap may benefit patients who have a total glossectomy by allowing them to achieve a more functional recovery.

Influence of neuromuscular block, mode of ventilation and respiratory cycle on pharyngeal mucosal pressures with the laryngeal mask airway

We tested the hypothesis that the pressure exerted by the laryngeal mask airway (LMA) against the pharyngeal mucosa varied with neuromuscular block, mode of ventilation and the respiratory cycle. We studied 20 anaesthetized adult patients. Microchip sensors were attached to a size 5 LMA at locations approximately corresponding to the base of the tongue, hypopharynx, lateral pharynx, oropharynx, posterior pharynx and piriform fossa. Mucosal pressures were measured with an intracuff pressure of 60 cm H2O under four conditions during anaesthesia using 2.0 MAC of sevoflurane: (1) apnoeic, non-paralysed; (2) spontaneously breathing, non-paralysed; (3) ventilated, paralysed and (4) non-ventilated, paralysed. In conditions (2) and (3), mucosal pressures were measured at the end of inspiration and expiration. Mean mucosal pressure was less than 10 cm H2O at all locations. There were no significant changes in mucosal pressure at any location between the four conditions. There was no variation between inspiration and expiration. With an intracuff pressure of 60 cm H2O in these circumstances, mucosal pressures were much less than considered safe for prolonged tracheal intubation.

The Innervated Gracilis Musculocutaneous Flap for Total Tongue Reconstruction

A functional neotongue following total glossectomy requires both soft-tissue bulk and reconstruction of muscle function. We used innervated transverse gracilis musculocutaneous flaps to reconstruct total glossectomy defects in eight patients. The obturator nerve to the gracilis muscle was approximated to the hypoglossal nerve to reinnervate the gracilis muscle by using microsurgical technique. The cutaneous paddle of the gracilis flap easily supplies sufficient bulk to replace the total glossectomy defect. Follow-up of patients ranged from 3 to 47 months. All patients were able to resume oral feeding. Electromyographic studies performed on one patient showed reinnervation of the flap with active elevation of the posterior pharynx. Ultimately, seven patients died because of recurrence of their disease. The innervated gracilis musculocutaneous flap may benefit patients who have a total glossectomy by allowing them to achieve a more functional recovery. (Plast. Reconstr. Surg. 104: 916, 1999.)

Mucosal pressures from the cuffed oropharyngeal airway vs the laryngeal mask airway

We tested the hypothesis that pressures exerted on the pharyngeal mucosa by the laryngeal mask airway (LMA) and cuffed oropharyngeal airway (COPA) differ, in 20 male and 20 female adult patients. Microchip pressure sensors were attached to the LMA and COPA at four similar anatomical locations (base of the tongue, lateral pharynx, posterior pharynx and distal oropharynx) and two dissimilar locations (LMA, piriform fossa and hypopharynx; COPA, middle of the tongue and proximal oropharynx). Cuff volume was adjusted until oropharyngeal leak pressure (OLP) was 10 cm H2O and mucosal pressures were recorded. This was repeated at an OLP of 15 cm H2O and at maximal OLP. Overall mucosal pressures were higher for the COPA than the LMA at 10 cm H2O (17 vs 3 cm H2O; P < 0.0001), at 15 cm H2O (21 vs 6 cm H2O; P < 0.0001) and at maximal OLP (26 vs 9 cm H2O; P < 0.0001). Mucosal pressures were always higher for the COPA at the base of the tongue, posterior pharynx and lateral pharynx, but were similar in the distal oropharynx. Maximal OLP was higher for the LMA than the COPA (27 (95% confidence intervals 25-29) vs 16 (12-19) cm H2O; P < 0.0001). We conclude that pressures acting on the mucosa were higher with the COPA compared with the LMA.

Laryngeal mask airway size selection in males and females: ease of insertion, oropharyngeal leak pressure, pharyngeal mucosal pressures and anatomical position

We have compared ease of insertion, oropharyngeal leak pressure, directly measured pharyngeal mucosal pressure and anatomical position (assessed fibreoptically) for the size 4 and size 5 laryngeal mask airway (LMA) in 20 male and 20 female patients. Microchip pressure sensors were attached to the LMA at locations corresponding to the piriform fossa, hypopharynx, base of the tongue, lateral and posterior pharynx, and the oropharynx. Oropharyngeal leak pressure, mucosal pressure and fibreoptic position were recorded during inflation of the cuff from 0 to 30 ml in 10-ml increments. In males, oropharyngeal leak pressure over the inflation range was higher for size 5 (21 vs 17 cm H2O; P = 0.01); mucosal pressure over the inflation range was higher in the posterior pharynx for size 4 (7 vs 2 cm H2O; P = 0.007), and higher in the piriform fossa (8 vs 5 cm H2O; P = 0.003) and hypopharynx (9 vs 5 cm H2O; P = 0.003) for size 5. In females, oropharyngeal leak pressure over the inflation range was the same (21 vs 21 cm H2O), but mucosal pressure over the inflation range was higher in the piriform fossa (21 vs 8 cm H2O; P = 0.003) and posterior pharynx (4 vs 2 cm H2O; P = 0.004) for size 4, and higher in the lateral pharynx (5 vs 1 cm H2O; P = 0.01) and oropharynx (11 vs 5 cm H2O; P = 0.009) for size 5. The distribution of mucosal pressure was different for size 4 between males and females, but not for size 5. For both males and females, fibreoptic position was similar. We conclude that the size 5 LMA is optimal in males, but either size is suitable for females. The shape of the pharynx may be different between males and females.

A Comparison of Pharyngeal Mucosal Pressure and Airway Sealing Pressure with the Laryngeal Mask Airway in Anesthetized Adult Patients

We measured pharyngeal mucosal pressures at six different locations on the laryngeal mask airway (LMA) and tested the hypothesis that the efficacy of the seal is not related to pharyngeal mucosal pressure.Twenty anesthetized, paralyzed adult patients were studied. Microchip sensors were attached to the size 5 LMA at locations corresponding to the lateral and posterior pharynx, the hypopharynx, the pyriform fossa, the base of tongue, and the oropharynx. Mucosal pressures and airway sealing pressures were recorded during inflation of the cuff from 0 to 40 mL in 10-mL increments. The highest mean mucosal pressure was in the oropharynx (26 cm H2 O), and the lowest was in the posterior pharynx (2 cm H2 O). Mucosal pressures increased with increasing intracuff pressure and cuff volume, but the rate of increase varied among locations. Airway sealing pressure increased with increasing intracuff volume from 0 to 10 mL (P < 0.0001) and 10 to 20 mL (P = 0.0001), was unchanged from 20 to 30 mL, and decreased from 30 to 40 mL (P = 0.005). The airway sealing pressure was higher than pharyngeal mucosal pressure until the intracuff volume was >or=to30 mL. There was no correlation between mucosal pressures and airway sealing pressure at any location. We conclude that the efficacy of the seal is not related to pharyngeal mucosal pressure. Pharyngeal mucosal pressures are generally lower than those considered safe for the tracheal mucosa during prolonged intubation. Implications: We measured pharyngeal mucosal pressures at six different locations on the laryngeal mask airway and showed that the efficacy of the seal is not related to pharyngeal mucosal pressure. Pharyngeal mucosal pressures are generally lower than those considered safe for the tracheal mucosa during prolonged intubation. (Anesth Analg 1998;87:1379-82)

Angioarchitectural structure and functional distributive pattern of the filiform papillae on the meso-dorsal surface of the rabbit tongue

The angioarchitectural classification and distributive patterns were investigated in the filiform papillae (FiP) on the meso-dorsal surface of the rabbit tongue by using microvascular cast specimens (MVCS) and the scanning electron microscope (SEM). The author examined the microvascular network structures, which consisted of ascending and descending branches entering the FiP. They inclined in a posterior (pharynx) direction, and densely and geometrically covered the meso-dorsal surface, directing the spoon-like concave face in an anterior direction. FiPs could be classified into three types: a small filiform papilla (SfP) covering on the meso-dorsal surface except for the marginal part of the intermolar eminence (MIME) and the intermolar eminence itself (IME): a spoon-like concave structure facing in an anterior (apex) direction with an arrowhead-like top: a middle filiform papilla (MfP) on the MIME, made up of a long triangle-like concave structure with a sharp arrowhead-like top and inclined at right angles to the IME. A large filiform papilla (LfP) on the whole swelling dorsal area of the IME was formed by a long triangle-like concave structure with a sharper arrowhead-like top. LfPs are longer and larger than MfPs and inclined towards the pharynx.

Struggling toward easier endoscopy

Struggling toward easier endoscopy