Acute Sinusitis in the Rabbit Model: Histologic Analysis

Objectives: Characterize the histology of the rhinogenic model of sinusitis and compare this with existing models of sinusitis. Study Design: Prospective controlled trial in animals. Methods: New Zealand white rabbits were implanted with a synthetic sponge, which was then impregnated with Streptococcus pneumoniae bacteria. After a specified time the animals were sacrificed, and whole-mount sectioning of both the infected and noninfected sinuses was performed. The sinuses were carefully examined for evidence of inflammatory changes. Results: This model produced a sinus infection that is characterized by luminal exudates of neutrophils and eosinophils, mucosal infiltration with lymphocytes and plasma cells, and epithelial degeneration. In addition, discrete lymphoid follicles were identified in both the implanted and nonimplanted sides that in the implanted sides appear to hypertrophy and liberate leukocytes into the sinus lumen. Other areas were observed where luminal exudates seem to act on and degrade mucosa that has little or no underlying inflammation. In severely infected sinuses submucosal vacuole formation with overlying granulation tissue was observed. Conclusions: The rhinogenic model of sinusitis demonstrates features typical of other known models of sinusitis. In addition, there appear to be unique features of this model, specifically the identification of discrete lymphoid aggregates, which suggest that this model has the potential to be valuable for the study of the immune response of the sinuses.     

Comparison of Histopathological and CT Findings in Experimental Rabbit Sinusitis

The aim of this study was to investigate and compare histopathological and computerized tomographic (CT) findings of experimental acute sinusitis in an animal model. The noses of five healthy rabbits were inoculated with a gelatin sponge impregnated with a solution containing Staphylococcus aureus, and one healthy rabbit acted as the control. The animals were sacrificed on the tenth day, following the acquisition of paranasal CT scans. Specimens were obtained from the lateral nasal walls, and the ethmoid and maxillary sinuses of the animals for histopathological examination. Histopathological and CT findings were compared. Various degrees of epithelial disorganization, foci of ruptured epithelial cells, and inflammatory cell infiltration in the lamina propria were seen in the histopathological examinations of the five study rabbits, and mucosal thickening and soft tissue density were noted in their CTs. There was no correlation between the histopathological and CT findings. It was shown that CT did not reflect the acute changes in the sinus mucosa. Patients with chronic sinusitis must be evaluated for a chronic process. Computerized tomographic scans should not be obtained in acute sinusitis cases. In this way, both unnecessary radiation exposure and economic waste can be avoided.     

Prediction of the Clinical Outcome of Acute Frontal Sinusitis With Ventilation Measurement of the Nasofrontal Duct After Trephination: A Long-Term Follow-up Study

Acute frontal sinusitis has become an increasing clinical problem in the region that is served by the hospital represented by the authors of this study. The standard surgical treatment protocol after the failure of conservative therapy has been to perform trephination of the involved frontal sinus. More sophisticated procedures have been used in patients with prolonged or recurrent disease. The authors have developed a simple ventilation test of the nasofrontal duct that can be used to determine which patients require further surgery. In a long-term follow-up study of 85 patients, this ventilation test was shown to predict the cases that would heal uneventfully after trephination and the cases that would require further surgery because of an obstructed nasofrontal duct. The findings of this study are of special interest for modern functional endoscopic sinus surgery, the purpose of which is to open up the nasofrontal region.     

Sinusitis in immunocompromised patients. A multicenter study

This paper evaluates different aspects of sinusitis in patients with a decreased immunological system, such as its prevalence and clinical evolution, its peculiar bacteriology and the altered response to treatment, and the prognosis, especially in patients with AIDS. There seems to be an increased prevalence of sinusitis in these patients, with a relationship between their immunological status and the severity and aggressiveness of the sinusitis. Bacteriological studies reveal the pressure of more aggressive species, such as P. aeruginosa, and specific sinusitis are more frequent, which may explain why the treatment with common antibiotics often remains uneffective. The simultaneous therapy of concomitant infections leads to a higher resistance towards common drugs. A standard treatment is therefore needed. The results of three studies, retrospective and prospective, on HIV-infected patients reveal a high incidence of acute sinusitis with aggressive bacteria.     

Myringotomy Delays the Tympanic Membrane Recovery in Acute Otitis Media: A Study in the Rat Model

Background/Hypothesis Acute otitis media is a major cause of visits to pediatric health care providers. Myringotomy in uncomplicated acute otitis media is debatable today. The study addressed this problem through the otomicroscopic and histopathological observations of the events occurring in the tympanic membrane during the first week after myringotomy. Study Design Randomized study in an experimental animal model. Methods Under anesthesia, the left middle ear of 36 Sprague‐Dawley rats was inoculated with Streptococcus pneumoniae type 3. Forty‐eight hours later, at day 0, four animals were immediately killed and the remaining animals were randomly assigned into a myringotomy group (n = 16, myringotomy on the left ear) and a non‐myringotomy group (n = 16, otomicroscopy without myringotomy). Otomicroscopy and killings were performed in series of four animals from each group at days 1, 2, 4, and 7 after myringotomy. Tympanic membranes were collected after fixation and processed for light and electron microscopy. Results All inoculated ears showed a manifest acute otitis media at day 0. An intense infiltration by inflammatory cells and edema distorted severely the tympanic membrane structure. These findings decreased the following days. However, inflammation as evaluated by the thickness and the cytoarchitecture of the tympanic membrane layers, recovered significantly faster in the membranes in the non‐myringotomy group. At day 7, all tympanic membranes in the myringotomy group were closed by a hypertrophic keratinizing epithelium and a remodeling connective tissue layer, whereas the animals in the non‐myringotomy group had a residual edema in the lamina propria. Conclusions The present infectious model induced an intense inflammatory reaction within the entire structure of the tympanic membrane. Myringotomy provoked a delayed recovery from the inflammatory process within the tympanic membrane. Therefore, if applicable to human conditions, the use of myringotomy in the management of acute otitis media should be restricted to selected cases of acute otitis media.     

Sinusitis in the nasotracheally intubated patient

Maxillary sinusitis as a complication of nasotracheal intubation has long been recognized as difficult to diagnose and equally difficult to treat. To better define this problem from a diagnostic and therapeutic standpoint, we studied patients admitted to the surgical intensive care unit at the University of Texas Health Science Center at Houston-Hermann Hospital over a six-month period. During this time, we identified 19 cases of maxillary sinusitis. Diagnostic criteria included fever, leukocytosis, purulent rhinorrhea, and maxillary sinus opacification or air fluid level noted on sinus roentgenograms. Patients who met these criteria underwent maxillary sinus aspiration. Sixteen patients were receiving antibiotic therapy when sinusitis was diagnosed. All patients had their endotracheal tubes replaced orally, had diseased maxillary antra lavaged, and underwent appropriate antibiotic therapy guided by culture and sensitivity studies. Four of 19 patients required more than one sinus lavage, but all patients had their sinus disease resolve. These data suggest an aggressive approach to diagnosing sinusitis in the nasotracheally intubated patient is needed. A maxillary sinus aspiration and lavage should be an integral part of the diagnosis and treatment of these patients.     

Sinusitis,Otitis And Adenotonsillitis In Children: A Retrospective Study

A retrospective study of 93 cases in which ventilating tubes were required in the therapy of persistent otitis media. Paranasal sinus radiographs, antral washes and cultures of positive washes were used to demonstrate active sinusitis associated with persistent otitis media. Other factors are also of importance, such as allergic or other immune-related disease processes. However, active sinusitis was demonstrated in 25–49% of the cases studied, depending on criteria used.     

Sinusitis and the acute orbit in children

Acute orbital infection is an uncommon condition which is often secondary to acute sinusitis. Although it can present in any age group it is most prevalent in children and may cause impaired vision, blindness, intracranial complications and death. This paper documents the experience at the Royal Liverpool Childrens Hospital, Alder Hey, from 1973 to 1989. Clinical details were recorded retrospectively from the hospital case notes. Sixty-eight children had orbital sepsis of whom 30 had associated acute sinusitis. Of these 30 children, orbital sepsis was always unilateral with a preference for the left side; ten had diplopia of whom four had a sub-periosteal abscess which was subsequently drained. There were no serious complications although two children had diplopia for two to three months.     

Application of an Intraoperative Neuromonitoring System Using a Surface Pressure Sensor in Parotid Surgery: A Rabbit Model Study

ObjectivesFacial nerve monitoring (FNM) can be used to identify the facial nerve, to obtain information regarding its course, and to evaluate its status during parotidectomy. However, there has been disagreement regarding the efficacy of FNM in reducing the incidence of facial nerve palsy during parotid surgery. Therefore, instead of using electromyography (EMG) to identify the location and state of the facial nerve, we applied an intraoperative neuromonitoring (IONM) system using a surface pressure sensor to detect facial muscle twitching. The objective of this study was to investigate the feasibility of using the IONM system with a surface pressure sensor to detect facial muscle twitching during parotidectomy.MethodsWe evaluated the stimulus thresholds for the detection of muscle twitching in the orbicularis oris and orbicularis oculi, as well as the amplitude and latency of EMG and the surface pressure sensor in 13 facial nerves of seven rabbits, using the same stimulus intensity.ResultsThe surface pressure sensor detected muscle twitching in the orbicularis oris and orbicularis oculi in response to a stimulation of 0.1 mA in all 13 facial nerves. The stimulus threshold did not differ between the surface pressure sensor and EMG.ConclusionThe application of IONM using a surface pressure sensor during parotidectomy is noninvasive, reliable, and feasible. Therefore, the IONM system with a surface pressure sensor to measure facial muscle twitching may be an alternative to EMG for verifying the status of the facial nerve.     

下食管括约肌球囊扩张建立咽喉反流性疾病兔模型

目的 探讨通过下食管括约肌(lower esophageal sphincter,LES)扩张建立咽喉反流性疾病(laryngo-phyngeal reflux disease,LPRD)模型的可行性.方法 18只新西兰白兔随机分为实验组10只和对照组8只,对实验组动物进行L ES测压定位后,使用球囊对L ES进行注水...     

Sinusitis in patients with the acquired immunodeficiency syndrome

AIDS patients suffer from multiple immunologic deficits involving humoral and cell-mediated immunity. The humoral deficits place the patient at a higher risk for recurrent bacterial infection than the general population. Sinusitis has been recognized to be a more common problem in AIDS patients than was previously appreciated. A high level of clinical suspicion is important, especially in patients with fever, headaches, or symptoms referrable to the upper respiratory tract. Should sinusitis be demonstrated, aggressive medical management is indicated. Surgical drainage is indicated in patients who worsen in spite of appropriate medical therapy, patients who have signs of systemic toxicity from the sinusitis that do not rapidly improve, and patients with recurrent sinusitis. Further studies are indicated to determine the true incidence of sinusitis in the AIDS population and to elucidate further the immunologic defects involved.     

Endoscopically Applied Biodegradable Stent in a Rabbit Model of Pediatric Tracheomalacia

ObjectivesA polydioxanone (PDO) stent was developed to treat tracheomalacia in pediatric patients. However, its safety and efficacy need to be verified in animal studies before clinical trials in patients can be conducted. This study evaluated the safety and efficacy of a PDO stent in normal and tracheomalacia-model rabbits.MethodsIn total, 29 New Zealand white rabbits were used: 13 for evaluating the biocompatibility of the PDO stent in normal rabbits and 16 for the creation of a tracheomalacia model. The tracheomalacia model was successfully established in 12 rabbits, and PDO stents were placed in eight of those rabbits.ResultsThe PDO stent was successfully positioned in the trachea of the normal rabbits using an endoscopic approach, and its degradation was observed 10 weeks later. The stent fragments did not induce distal airway obstruction or damage, and the mucosal changes that occurred after stent placement were reversed after degradation. The same procedure was performed on the tracheomalacia-model rabbits. The survival duration of the tracheomalacia rabbits with and without stents was 49.0±6.8 and 1.0±0.8 days, respectively. Thus, the PDO stent yielded a significant survival gain (P=0.001). In the tracheomalacia rabbits, stent degradation and granulation tissue were observed 7 weeks after placement, leading to airway collapse and death.ConclusionWe successfully developed a PDO stent and an endoscopic guide placement system. The degradation time of the stent was around 10 weeks in normal rabbits, and its degradation was accelerated in the tracheomalacia model. The mucosal changes associated with PDO stent placement were reversible. Placement of the PDO stent prolonged survival in tracheomalacia-model rabbits.