Internal Auditory Canal Diverticula among Pediatric Patients: Prevalence and Assessment for Hearing Loss and Anatomic Associations.

BACKGROUND AND PURPOSE: Internal auditory canal diverticula are focal lucencies along the anterior-inferior aspect of the internal auditory canal fundus. Studies in adults report conflicting data on the etiology and clinical relevance of this finding. We would expect a pediatric study to help elucidate the significance of internal auditory canal diverticula. The primary goals of this study were to determine the temporal bone CT prevalence of diverticula among pediatric patients and to assess possible hearing loss and anatomic associations. MATERIALS AND METHODS: For this retrospective study including 283 pediatric temporal bone CTs, 4 neuroradiologists independently assessed for diverticula. Discrepancies were resolved by consensus. One neuroradiologist assessed for an enlarged vestibular aqueduct, labyrinthine dysplasia, cochlear cleft, and otospongiosis. Patient demographics, audiologic data, and pertinent clinical history were recorded. One-way analysis of variance and the Fisher exact test were used to assess possible associations between diverticula and specific patient characteristics. RESULTS: Diverticula were observed in 42/283 patients (14.8%) and were more commonly bilateral. There was no significant association with age, sex, hearing loss, enlarged vestibular aqueduct, labyrinthine dysplasia, or cochlear cleft. A statistically significant association was observed with otospongiosis (P = .013), though only 1 study patient had this disease. CONCLUSIONS: Internal auditory canal diverticula are a common finding on pediatric temporal bone CT. In the absence of clinical or imaging evidence for otospongiosis, diverticula likely fall within the range of a normal anatomic variation. Familiarity with these findings may prevent neuroradiologists from recommending unnecessary additional testing in pediatric patients with isolated internal auditory canal diverticula.

Surgical management of retropharyngeal space infections in children.

OBJECTIVE: To study the perioperative management strategies in a large group of pediatric patients undergoing surgical therapy for suppurative adenitis of the parapharyngeal and retropharyngeal spaces. STUDY DESIGN: Retrospective analysis of all patients treated surgically from January 1, 1989, to December 31, 1998, in a tertiary care pediatric hospital. METHODS: Charts were reviewed for demographic data, duration and nature of symptoms, radiological workup, surgical approach, complications, duration of medical therapy and antibiotic choice, and bacteriological findings. Computed tomography (CT) results were correlated to surgical findings. RESULTS: A dramatic increase in the incidence of deep neck space infection was seen during the study period; this increase was congruent with the increase in culture-positive group A beta-hemolytic streptococcal abscesses. More than two-thirds of the patients were boys with the peak incidence being in the 3- to 5-year-old group. The duration of symptoms before presentation was less than might be expected, especially in the younger age groups. Seventy of 73 children were treated with a transoral approach. Sixty-eight of 73 were successfully treated with one operative intervention. Irregularity of the abscess wall was found to be a stronger predictor of the presence of pus than the presence of ring enhancement. CONCLUSIONS: The current study represents the largest series of pediatric retropharyngeal abscesses in the modern medical literature. Changes in the disease process and in management from the first half of the century to today are reviewed, and recommendations for optimal management presented. The data in this series support a transoral approach to these abscesses unless there is extension lateral to the great vessels.

Mortality following adenotonsillectomy in a patient with Williams-Campbell syndrome.

Adenotonsillectomy is a commonly performed procedure that can greatly change airway pressure in patients with obstructive sleep patterns related to enlarged tonsils and adenoids. A case is presented in which a patient with a rare subclinical form of Williams-Campbell syndrome died after outpatient adenotonsillectomy. This case report illustrates how patients with structural abnormalities of the tracheobronchial tree can be at increased risk for complications when undergoing surgical procedures that impact airway dynamics.

Neurotic effects of doxycycline sclerotherapy.

A patient experienced phrenic nerve paralysis after doxycycline sclerotherapy for treatment of chylous fistula at our institution. The purpose of this study is to use physiologic testing to determine whether doxycycline is capable of inducing defects in neural function. A nonrandomized, controlled trial was performed with nerve-conduction studies to determine possible deleterious effects of doxycycline sclerotherapy. Thirty-eight CD rats were used and separated into four groups. Doxycycline was applied to the sciatic nerves of rats by either topical application directly on the nerve or by intraneural injection. Nerve-conduction studies were done before surgery and at 1,7, and 21 days after surgery. The results showed a statistically significant decrement in nerve-conduction velocity and strength of transmitted impulse in those nerves injected with doxycycline solution. Complete nerve block was seen frequently. This effect was not seen with topical application of doxycycline or normal saline solution or with intraneural injection of normal saline solution. This study demonstrates that doxycycline can induce a marked decrement in neural function when applied to the subepineural layers of the sciatic nerve in the rat. Therefore doxycycline sclerotherapy should be used with great caution in situations in which it could become exposed to nerves that have sustained surgical trauma.

A scanning electron microscopic study of arterial endothelial repair under turbulent flow conditions.

In order to study the role of hemodynamic factors on the healing and native morphology of endothelium in vivo, turbulent arterial flow was created using a loop bypass model, with and without occlusion in the recipient vessel. In this model, several different patterns of turbulent arterial blood flow resulted. The scanning electron microscope (SEM) was used to evaluate endothelial morphology in the area of the anastomoses at 3 and 14 days post-operatively. Morphological changes in the native endothelium along the recipient vessel correlated well with the direction of blood flow and predicted patterns of turbulence. The morphology of the native endothelium was altered to reflect the direction and pattern (laminar versus turbulent) of blood flow by 3 days postoperatively. Based on endothelial morphology, very narrow zones of separation could be demonstrated between areas of laminar and turbulent blood flow. The degree of reendothelialization across the suture itself was greatly variable at 3 days and there seemed to be no relationship to the location of turbulent flow.

A new syndrome: heart defects, laryngeal anomalies, preaxial polydactyly, and colonic aganglionosis in sibs.

We present two siblings, one male and one female, who have heart defects, duplication of toes, airway anomalies, and aganglionosis. The brother also has a bilateral complete cleft lip and palate. His airway anomalies include short epiglottis and aryepiglottic folds, which are different from his sister who has a bifid epiglottis with a central epiglottic mass. Both siblings have had some developmental delay. This constellation of anomalies appears to be unique and may represent a new autosomal recessive disorder.

Construction of a vein-pouch aneurysm at a surgically created carotid bifurcation in the rat.

Currently available animal models for the study of treatment of aneurysms are either expensive or yield unreliable results. An animal series was devised to address both of these problems by creating a new animal model. Twelve Sprague-Dawley rats were used to demonstrate that a vein-pouch aneurysm could be constructed at a surgically created carotid bifurcation. Patency rates, growth dynamics, and histologic morphology were studied at three time intervals. A 100% patency rate at the aneurysm orifice was achieved with one-third of the aneurysms showing varying degrees of partial apical thrombosis. A growth pattern was established over the study period. Magnetic resonance angiography and digital subtraction angiography were successfully employed to study a small number of additional aneurysms. Our conclusion is that a bifurcation aneurysm can be constructed in the rat with high patency rates and predictable saccular morphology which resembles most human intracranial aneurysms. This inexpensive animal model can be used to study novel modalities for the treatment of aneurysms.

Histologic effect of doxycycline sclerotherapy on rat femoral nerve.

BACKGROUND: This study stems from an encounter with a phrenic nerve paralysis in a patient following doxycycline sclerotherapy for treatment of chylous fistula. The purpose of this study is to identify possible histologic evidence of doxycycline-induced nerve injury. METHODS: The femoral nerves of CD rats were used as the in vivo animal model. The nerves were exposed to varying concentrations doxycycline and normal saline was the control. The nerves were studied at several time intervals using two different staining techniques. RESULTS: The results suggest that topical doxycycline induces tissue reactions which are different from normal saline. These reactions include stimulation of a local giant cell inflammatory reaction and disruption of the myelin sheath. CONCLUSIONS: Despite the fact that this study does not give physiologic evidence of neurotoxicity, the histologic results suggest that topical doxycycline may cause nerve damage directly or indirectly. We conclude that doxycycline should not be used for sclerotherapy where unprotected nerves are exposed to the agent until further physiologic tests are performed to prove its safety.

Intraoperative recurrent laryngeal nerve monitoring during video-assisted throracoscopic surgery for patent ductus arteriosus.

OBJECTIVE: To develop a technique to identify and localize the recurrent laryngeal nerve (RLN) during video-assisted thoracoscopic surgery (VATS) for patent ductus arteriosus. DESIGN: Prospective clinical study. SETTING: Children's hospital. PARTICIPANTS: Sixty infants and children scheduled for elective closure of patent ductus arteriosus. INTERVENTIONS: With parental informed consent, 60 infants and children undergoing elective VATS for patent ductus arteriosus were studied. A thin, pencil-point, Teflon-coated, stimulating probe allowed direct stimulation (<2 mA, 100-msec pulse width) of the left RLN inside the thorax. A commercially available 4-channel neurologic monitor recorded compound evoked electromyograms (EMGs) from the left RLN and right RLN (as control) by needle electrodes placed percutaneously in the neck. Hoarseness, stridor, feeding difficulties, and voice changes were assessed postoperatively. MEASUREMENTS AND MAIN RESULTS: Left RLN EMGs were easily obtained in 59 of the 60 patients. The surgeon correctly identified the RLN visually once in the first 7 patients; this ability subsequently improved. EMG localization of the location or course of the RLN altered dissection, clip size, or clip position in 37 of 59 patients. CONCLUSION: Intraoperative EMG to identify location and route of the RLN was easy to perform, was effective in identifying RLN position, and appeared to facilitate dissection and clipping of the ductus.