Background:Pneumosinus dilatans (PSD) is a rare pathological paranasal sinus expansion. This condition is usually symptomatic or cosmetically apparent, requiring surgical intervention. Multiple hypotheses have been postulated as to the cause of this condition; however, the precise cause and pathogenesis remain obscure.Case report and Methods:An 11-year-old boy presented with right eye bulging and was subsequently found to have PSD of the maxillary sinus. A search was conducted of the PubMed electronic database, using the keywords “pneumosinus dilatans,” “pneum(oco)ele,” “pneum(oc)ele,” “pneum(atoco)ele,” and “air cyst.” Articles published in English were reviewed.Results:The literature review identified 29 cases of PSD involving the maxillary sinus. The mean age of presentation was 25 years old. Only the right maxillary sinus was affected in 16 cases, followed by the bilateral sinuses in 7 cases and the left sinus in 6 cases. In 5 cases, all paranasal sinuses, along with the maxillary sinus, were expanded. The most common presenting symptom was facial swelling, which was found in 55% of the cases, followed by proptosis and pain. Computed tomography is the gold standard radiological method for diagnosing PSD.Conclusions:Pneumosinus dilatans is a rare condition that is usually symptomatic and requires surgical intervention. The etiology of the disease is attributed to multiple hypotheses, but more studies are needed to explore this condition further.

Background The prevalence of allergic fungal rhinosinusitis (AFRS) and its associated risk factors have been an issue of debate. Some epidemiological factors have been correlated to the disease prevalence. Objectives To observe the prevalence pattern of AFRS worldwide and to investigate the effect of specific epidemiological factors on the disease prevalence. Methods A systematic review was derived from 1983 to December 2018. Data on the prevalence of AFRS were collected from the selected studies. Relevant factors assessing each city's climate, socioeconomics and geography were used to study the association with AFRS prevalence. Results 35 cities across 5 continents were investigated. The worldwide average rate of AFRS in CRS cases is 7.8% (0.2%–26.7%) in which more than half of the investigated cities (57%) had low AFRS prevalence, while the remaining cities had intermediate (11%) and high (32%) prevalence. Cities with higher temperatures were associated with a higher prevalence of AFRS ( p-value 0.002), whereas cities with humid continental climate were significantly associated with a low prevalence of AFRS ( p-value 0.032). Humidity and wind speed were lower in the cities with higher AFRS prevalence ( p-value 0.018 and 0.008, respectively). There were no significant correlations between AFRS prevalence and economic levels, presence of water bodies, rainfall amounts, altitude, and presence of forests. Conclusion AFRS has a worldwide distribution pattern with varying prevalence. In this ecological study, we observed a correlation between AFRS prevalence and climatic factors (climate classification, humidity, temperature, and wind speed). Socioeconomic factors should be analyzed on an individual basis for better assessment of the relationship with disease prevalence.

Objectives: To address the factors affecting recurrence after endoscopic surgical repairs of spontaneous cerebrospinal fluid leak, specifically the influence of using lumbar drains. Methods: This study involved a retrospective data analysis, including a chart review of all spontaneous cerebrospinal fluid (CSF) leak cases who underwent endoscopic anterior skull base repair from 2012-2017 in King Fahad Medical City, Riyadh, Kingdom of Saudi Arabia. Original Articles Results: Thirteen patients with spontaneous CSF leaks were identified and evaluated. The majority were females (92.3%) with an average body mass index of 34.9. All patients underwent endoscopic repair with intra-operative lumbar drain placement. Patients continued having post-operative lumbar drain for an average of 6.4 days. Four patients (30.8%) developed recurrence; however, only one of those had a documented high opening pressure. Conclusion: Spontaneous CSF leak repairs are at a higher failure risk and may have an underlying pathology involving CSF circulation. The use of lumbar drains and intracranial pressure lowering agents are controversial and seems to be reserved only for high risk patients; however, the higher risk of recurrence in this group may be better managed by proper pre-operative evaluation and selective, patientspecific management protocols.

Background Cerebrospinal fluid leak (CSFL) repair simulation models are scarce; however, these models are valuable tools for skull base reconstruction surgery training. Objectives This study aims to assess the face, content, and construct validity of a CSFL repair simulation model. Method Eight novices (residents- PGY3) and eight experts have performed skull base reconstruction in multiple sites in twelve human cadaveric heads in simulated surgical environment. The experts completed a post-study 21-item questionnaire to assess the face and content validity. The performances of the participants were recorded and scored by two independent investigators who were blinded to the participant's level. Global Rating Scale of Operative Performance (GRSOP) and a Specific Skull Base Reconstruction Checklist (SBRC) were used to score the performances. Results The responses from the expert group for the 21-item questionnaire were high for all items (4.13–4.88 out of 5). The internal consistency reliability of the questionnaire and the intraclass correlation, which was derived by Cronbach’s Alpha, were 0.913 and 0.941 respectively. Differences in construct validity between the two groups were statistically significant for both the GRSOP and SBRS (P-value < 0.001). Conclusion We demonstrated the face, content, and construct validity of the CSFL repair simulation model, which facilitates the acquisition of technical skills necessary for skull base reconstruction surgery. The model includes realistic features that make it useful in educational courses.

Recurrence of allergic fungal rhinosinusitis (AFRS) is well recognized. However, there is scarcity in the literature describing involvement of the non-diseased sinuses. We aimed to evaluate the recurrence forms of unilateral AFRS as well as to study the possible predictor factors of developing the disease in the contralateral side. Patients with exclusive unilateral AFRS from (2010 to 2015) were enrolled in multi-institutional case-control study. All patients were evaluated after endoscopic sinus surgery for recurrence. Patient's records were reviewed for demographics, medical treatment, and clinical, radiological, and surgical data. A total of 68 patients were identified. Delayed contralateral involvement after the initial surgery was found in 30.8% with mean duration of recurrence 16.9 months. A significant association was found with the presence of pre-operative contralateral symptoms and signs of inflammation (OR 3.49, 95% CI 1.19-10.22, p value 0.02). Post-operative use of budesonide irrigation was associated with less contralateral involvement (OR 0.11, 95% CI 0.01-0.87, p value 0.01). Association of other variables like: comorbidities, perioperative use of systemic steroid, radiological signs, extent of surgery, additional surgery to the contralateral side, and post-operative use of systemic steroids did not show statistical significance. Involvement of the contralateral sinuses in 30% of unilateral AFRS cases is considered significant. The non-diseased sinuses should be involved in the routine endoscopic examination and post-operative treatment. Further studies are necessary to investigate the possibility of prophylactic surgical intervention of the non-diseased sinuses.