Microdebrider resection of bilateral subglottic cysts in a pre-term infant: a novel approach.

Acquired subglottic cysts are a rare cause of stridor in infants. The two major risk factors for development of these cysts are prematurity and history of intubation. Microlaryngeal decompression and carbon dioxide laser resection of these cysts have been the most common treatment methods with recurrence rates as high as 43% [J. Lim, W. Hellier, J. Harcourt, S. Leighton, D. Albert, Subglottic cysts: the Great Ormond Street experience, Int. J. Pediatr. Otorhinolaryngol. 67 (2003) 461-465]. Carbon dioxide laser therapy also carries the risk of airway fire, injury to adjacent structures, and possible delayed scarring. We present a case of bilateral subglottic cysts in a premature infant with progressive stridor, treated using a microdebrider, and review the literature regarding the treatment of these lesions.

Biofilm formation by Pseudomonas aeruginosa on ossicular reconstruction prostheses.

PURPOSE: Ossicular chain reconstruction may be complicated by prosthesis extrusion. As prostheses are commonly placed in middle ears contaminated with biofilm-forming bacteria, such as Pseudomonas aeruginosa (PA), extrusion may be caused by development of a biofilm on the prosthesis and the host response to this biofilm. The purpose of this experiment was to determine if PA forms biofilm on different ossicular chain reconstruction prostheses to a different degree. METHODS: Prostheses made of titanium, hydroxylapatite (HA), and plastic (23 each) were cultured with PA in broth for 96 hours. Biofilm formation was assessed by electron microscopy and quantitative microbiology. RESULTS: Titanium prostheses formed less biofilm than plastic (P = .0003) and HA (P = .003), but there was no difference between HA and plastic. Correction for surface area did not alter these significant differences. CONCLUSIONS: Pseudomonas aeruginosa forms biofilm on ossicular prostheses, particularly those made of plastic and HA. These differences could, in part, explain the extrusion propensity of certain biomaterials.

A perpetual switching system in pulmonary capillaries.

Of the 300 billion capillaries in the human lung, a small fraction meet normal oxygen requirements at rest, with the remainder forming a large reserve. The maximum oxygen demands of the acute stress response require that the reserve capillaries are rapidly recruited. To remain primed for emergencies, the normal cardiac output must be parceled throughout the capillary bed to maintain low opening pressures. The flow-distributing system requires complex switching. Because the pulmonary microcirculation contains contractile machinery, one hypothesis posits an active switching system. The opposing hypothesis is based on passive switching that requires no regulation. Both hypotheses were tested ex vivo in canine lung lobes. The lobes were perfused first with autologous blood, and capillary switching patterns were recorded by videomicroscopy. Next, the vasculature of the lobes was saline flushed, fixed by glutaraldehyde perfusion, flushed again, and then reperfused with the original, unfixed blood. Flow patterns through the same capillaries were recorded again. The 16-min-long videos were divided into 4-s increments. Each capillary segment was recorded as being perfused if at least one red blood cell crossed the entire segment. Otherwise it was recorded as unperfused. These binary measurements were made manually for each segment during every 4 s throughout the 16-min recordings of the fresh and fixed capillaries (>60,000 measurements). Unexpectedly, the switching patterns did not change after fixation. We conclude that the pulmonary capillaries can remain primed for emergencies without requiring regulation: no detectors, no feedback loops, and no effectors-a rare system in biology. NEW & NOTEWORTHY The fluctuating flow patterns of red blood cells within the pulmonary capillary networks have been assumed to be actively controlled within the pulmonary microcirculation. Here we show that the capillary flow switching patterns in the same network are the same whether the lungs are fresh or fixed. This unexpected observation can be successfully explained by a new model of pulmonary capillary flow based on chaos theory and fractal mathematics.

Heterogeneous capillary recruitment among adjoining alveoli.

Pulmonary capillaries recruit when microvascular pressure is raised. The details of the relationship between recruitment and pressure, however, are controversial. There are data supporting 1). gradual homogeneous recruitment, 2). sudden and complete recruitment, and 3). heterogeneous recruitment. The present study was designed to determine whether alveolar capillary networks recruit in a variety of ways or whether one model predominates. In isolated, pump-perfused canine lung lobes, fields of six neighboring alveoli were recorded with video microscopy as pulmonary venous pressure was raised from 0 to 40 mmHg in 5-mmHg increments. The largest group of alveoli (42%) recruited gradually. Another group (33%) recruited suddenly (sheet flow). Half of the neighborhoods had at least one alveolus that paradoxically derecruited when pressure was increased, even though neighboring alveoli continued to recruit capillaries. At pulmonary venous pressures of 40 mmHg, 86% of the alveolar-capillary networks were not fully recruited. We conclude that the pattern of recruitment among neighboring alveoli is complex, is not homogeneous, and may not reach full recruitment, even under extreme pressures.

Blood flow switching among pulmonary capillaries is decreased during high hematocrit.

Pulmonary capillary perfusion within a single alveolar wall continually switches among segments, even when large-vessel hemodynamics are constant. The mechanism is unknown. We hypothesize that the continually varying size of plasma gaps between individual red blood cells affects the likelihood of capillary segment closure and the probability of cells changing directions at the next capillary junction. We assumed that an increase in hematocrit would decrease the average distance between red blood cells, thereby decreasing the switching at each capillary junction. To test this idea, we observed 26 individual alveolar capillary networks by using videomicroscopy of excised canine lung lobes that were perfused first at normal hematocrit (31-43%) and then at increased hematocrit (51-62%). The number of switches decreased by 38% during increased hematocrit (P < 0.01). These results support the idea that a substantial part of flow switching among pulmonary capillaries is caused by the particulate nature of blood passing through a complex network of tubes with continuously varying hematocrit.

Acquired cholesteatoma presenting as a pars squamosa temporal bone mass.

Acquired cholesteatomas typically arise in the middle ear and mastoid cavities; they rarely present elsewhere. We describe a case of acquired cholesteatoma that presented as a large mass of the pars squamosa of the temporal bone in a 16-year-old girl. The mass was surgically removed without complication. To the best of our knowledge, this is only the second reported case of an acquired cholesteatoma in the lateral temporal bone.

Pediatric tracheotomy wound complications: incidence and significance.

OBJECTIVES: To determine the incidence and to describe wound complications and associated risk factors of pediatric tracheotomy. DESIGN: Retrospective case series. SETTING: Freestanding tertiary care academic pediatric hospital. PATIENTS: Sixty-five consecutive children undergoing tracheotomy over 15 months. MAIN OUTCOME MEASURES: Postoperative wound complications objectively and independently documented by an advanced practice nurse specializing in tracheotomy care. Secondary outcome measures included comorbidities, mortality rates, and wound status after subsequent examinations and management. RESULTS: The mean (SEM) patient age at tracheotomy was 45 (8.7) months (median age, 9.1 months). The most common indication for tracheotomy was pulmonary disease (36.9%), followed by neurologic impairment and laryngeal abnormalities. There were 19 patients (29%) with and 46 patients (71%) without wound complications. There were no significant differences between the 2 groups in age (P = .68) or weight (P = .55); however, infants younger than 12 months had an increased complication rate (39% vs. 17%, P = .04). The type of tracheotomy tube was predictive of postoperative wound complications (P = .02). All patients with wounds received aggressive local wound care. Five of 13 patients had complete resolution of stomal wounds, whereas 8 patients had persistent wound issues. There were 5 non-wound-related mortalities. CONCLUSIONS: With attempts to classify tracheotomy wound breakdowns as reportable events, including never events, increasing emphasis is being placed on posttracheotomy care. This study demonstrates that wound breakdown in pediatric tracheotomy patients is common. These complications can be mitigated, although not prevented completely, with aggressive wound surveillance and specialized wound care.

Unexpected pathologies in pediatric parotid lesions: management paradigms revisited.

OBJECTIVES: To present case vignettes of unusual pediatric parotid pathologies and discuss management paradigms in the context of these lesions. STUDY DESIGN: Retrospective case series. SETTING: Free-standing, academic tertiary care pediatric hospital. METHODS: All patients over the past 18 months undergoing parotidectomy for a parotid mass were reviewed (N=5). RESULTS: Ages ranged from 17 months to 16 years. All presented with a remarkably similar clinical course, consisting of a persistent parotid mass for more than 3 months which was usually painless. Most (4/5 patients) had been treated with antibiotics prior to Otolaryngology consultation. Fine-needle aspiration (FNA) was performed on 3 patients and was diagnostic in one. Complete excision of the mass was performed in each child through a parotidectomy approach (3 total, 2 lateral lobe). The final pathology showed metastatic neuroblastoma (17 months old), undifferentiated primitive sarcoma (22 months old), mucoepidermoid carcinoma (11 years old), nodular fasciitis (12 years old), and hyperplastic lymph node (16 years old). The patient with neuroblastoma died from complications of bone marrow transplant. CONCLUSIONS: The differential diagnosis for a persistent pediatric parotid mass is expansive and differs from that found in the adult population. As this series highlights, in many cases, it is impossible to discern the pathology, or rule out malignancy, based upon the clinical course, imaging, or FNA results. Surgical excision remains the standard for management of these patients and is both diagnostic and therapeutic. Our anecdotal case series highlights the importance of having a low threshold for parotidectomy in these children.

Prolonged recovery after out-patient pediatric adenotonsillectomy.

OBJECTIVE: To determine variables predictive of recovery room times in pediatric outpatient adenotonsillectomy. STUDY DESIGN: Retrospective case-control. METHODS: One-hundred ninety consecutive patients undergoing outpatient adenotonsillectomy at an ambulatory surgery center of a tertiary-care free standing pediatric hospital were grouped into upper and lower deciles of recovery room times. Twenty-one variables were analyzed to determine which variables are predictive of prolonged recovery time. Univariate and multivariate analyses were performed. RESULTS: Of the 190 patients, mean recovery room time was 103 min (SD 53.1), 22 patients were in the lower decile (mean recovery room time of 63 ± 6 min) and 17 patients were in the upper decile (155 ± 40 min, P<0.0001). Of the 21 variables analyzed, post-anesthesia care unit (PACU) nursing staff was the only significant predictor of prolonged recovery room time. Compared with one PACU nurse, other nurses (N=5) predicted a longer recovery time (OR=10.8, 95% CI 2.0-59.5, P=0.0017). This association remained significant when controlling for anesthesiologist and surgeon (OR=8.8, 95% CI 1.5-50.9, P=0.0072). There were no complications in any patients. CONCLUSIONS: Recovery room times after outpatient adenotonsillectomy vary significantly (mean 103 min (SD 53.1), range 50-241 min). Of potential predictors, only the human factor (PACU nursing staff) was associated with prolonged recovery room times, independent of surgeon and anesthesiologist. Development of standardized protocols for nurses to use for discharge has the potential to increase throughput for adenotonsillectomy patients in an outpatient surgery center setting.

Polysomnographic variables predictive of adverse respiratory events after pediatric adenotonsillectomy.

OBJECTIVE: To determine polysomnographic (PSG) variables that may potentially predict adverse respiratory events after pediatric adenotonsillectomy. DESIGN: Retrospective, case-control study. SETTING: Free-standing academic tertiary-care pediatric hospital. PATIENTS: The study included 1131 patients undergoing adenotonsillectomy by 2 attending surgeons. There were no exclusion criteria. MAIN OUTCOME MEASURES: Variables from preoperative PSGs were analyzed to determine predictors of postoperative respiratory complications. Logistic regression analysis was performed. RESULTS: A total of 151 patients (13.4%) underwent preoperative PSG. Twenty-three of these patients (15.2%) had adverse respiratory events. The primary adverse event was desaturation requiring supplemental oxygen therapy, with 1 case of postobstructive pulmonary edema. Patients with adverse events had a significantly higher apnea-hypopnea index) (31.8 vs 14.1; P = .001), higher hypopnea index (22.6 vs 8.9; P = .004), higher body mass index (z score, 1.43 vs 0.70; P = .02), and lower nadir oxygen saturation (72% vs 84%; P <.001). Patients with adverse events had a prolonged hospital course (odds ratio, 32.1; 95% confidence interval, 7.8-131.4). There were no differences in age or other PSG variables. There were no intubations or mortalities. CONCLUSIONS: Polysomnography may be used to predict which patients are at higher risk for adverse respiratory events after adenotonsillectomy. Such knowledge is valuable for planning optimal postoperative management and intraoperative anesthesia. Predictors of increased respiratory complications include apnea-hypopnea index, hypopnea index, body mass index, and nadir oxygen saturation.

Multidisciplinary management of expanding bilateral neck hematomas in a patient with Hemophilia A with high-titer inhibitor.

There are multiple modalities by which trauma occurs to the neck. One of these includes minor suction trauma which usually results in a superficial bruising of the skin. While this usually self-resolves, patients with hemophilia are at higher risk for the development of bleeding from such trauma. Hematomas of the head and neck in patients with hemophilia have seldom been reported. We report a unique case of expanding bilateral neck hematomas secondary to suction trauma in a patient with Hemophilia A with high-titer inhibitor and highlight the importance of a multidisciplinary approach in the management of this complex patient.

Effect of ossicular prosthesis biofilms on middle ear scarring and hearing outcomes.

OBJECTIVES: Microbial biofilms have been associated with poor outcomes with a variety of biomedical implants; however, this relationship has not been established with ossicular chain reconstruction prostheses (ORPs). The purpose of this study was to determine if biofilms are present on ORPs in patients undergoing revision ossicular chain reconstruction and if their presence correlates with middle ear scarring or hearing outcomes. STUDY DESIGN: Prospective and blinded. SETTING: Tertiary referral center. PATIENTS: Patients undergoing revision ossicular chain reconstruction with previous ORP placement were enrolled. INTERVENTION/MAIN OUTCOME MEASURE: Ossicular chain reconstruction prostheses associated with poor hearing and residual or recurrent disease were cultured and examined using scanning electron microscopy. Audiometric thresholds and middle ear scarring scores were recorded. RESULTS: Twelve patients were included in the study. Of the prostheses, 25% were culture positive, and 67% had microscopic evidence of biofilm. No difference was found between the middle ear scarring scores (p = 0.31) and hearing outcomes (p = 0.11) of biofilm and nonbiofilm prostheses. There was no correlation between middle ear scarring and degree of conductive hearing loss (R2 = 0.04; p = 0.54). CONCLUSION: Biofilms are commonly found on ORPs at the time of revision ossicular chain reconstruction. The interaction between biofilms and the host environment is complex. Many factors besides biofilms may impact middle ear scarring and hearing.

Cochlear nerve diameter in normal hearing ears using high-resolution magnetic resonance imaging.

OBJECTIVES: Deficient cochlear nerves (CN) have been associated with poor cochlear implant performance. Normative data on CN diameter based on radiographic imaging have not been published. The objectives of this study were to determine if CN diameter could be reproducibly measured on parasagittal constructive interference in steady state (CISS)-sequence magnetic resonance imaging (MRI) and to establish a normative range for CN diameter. STUDY DESIGN: Retrospective review of MRI images by two independent blinded observers. METHODS: Thirty patients (45 ears) with a CISS-sequence MRI done for auditory complaints in patients with normal hearing in one ear were included. CN diameters were measured in a parasagittal plane just medial to the internal auditory canal (IAC) fundus by two independent observers. Cross-sectional areas were calculated and interobserver agreement was evaluated. RESULTS: The CN was identified in 100% of studied ears. In 93%, the diameters were able to be measured by both observers. In 7% of ears, the cochlear nerve was unable to be measured secondary to the proximity of the CN to IAC wall. The CN vertical diameter (1.4 mm +/- 0.21 mm), horizontal diameter (1.0 mm +/- 0.15 mm), and cross-sectional area (1.1 mm +/- 0.26 mm(2)) were normally distributed. There was good interobserver correlation for each measure. CONCLUSIONS: CN diameter can be reliably measured at the IAC fundus. This study establishes normative radiographic data for the CN diameter. These data may be used to evaluate the cause and treatment prognosis in patients with sensorineural hearing loss.