No abstract

Objective: We describe our experience using the extracorporeal video microscope, the “exoscope” for various applications within the field of lateral skull base surgery. Study Design: A retrospective case series was performed investigating patient demographics, indications for surgery, procedure type, operative time, approach to the skull base, complications, adequacy of visualization, and surgeon comfortability. Patients: Six cases were performed with a three dimensional surgical exoscope, obviating the use of a traditional binocular microscope. Setting: Academic, tertiary referral center. Main Outcome Measures: Type of surgical approach, operative time, patient demographics, surgical complications, and surgeon comfortability. Results: The following procedures were performed; four vestibular schwannoma resections via suboccipital craniotomy and two combined transmastoid and transtemporal approaches for temporal lobe encephalocele repairs. The average operative time was 227 and 577 minutes for temporal lobe encephalocele repairs and vestibular schwannoma cases, respectively. No intraoperative complications were encountered during these cases. None of the procedures required abandonment of the exoscope in favor of the microscope during the procedure. Advantages include high-resolution three-dimensional visualization, increased degrees of freedom for exoscope adjustment, and reduced surgeon fatigue in a fixed, unnatural posture. Limitations include decreased depth perception and increased operative time. Conclusion: The exoscope system is a safe and effective alternative or adjunct to the existing binocular operating microscope for lateral skull based procedures. The exoscope provides the surgeon with a comfortable, high-resolution visualization without compromising surgical exposure and patient safety. Level of evidence: 4

Objectives The Lund-Mackay (LM) staging system for Chronic Rhinosinusitis (CRS) does not correlate with clinical parameters, likely due to its coarse scale. We developed a “Modified Lund Mackay” (MLM) system, which uses a 3D, computerized method to quantify the volume of mucosal inflammation in the sinuses, and sought to determine whether the MLM would correlate with symptoms and disease-specific quality of life. Methods We obtained Total Nasal Symptom Score (TNSS) and Sinonasal Outcomes Test (SNOT-22) data from 55 adult subjects immediately prior to sinus imaging. The volume of each sinus occupied by mucosal inflammation was measured using MATLAB algorithms created using customized, image analysis software after manual outlining of each sinus. Linear regression was used to model the relationship between the MLM and SNOT-22 and TNSS. Correlation between the LM and MLM was tested using Spearman's rank correlation coefficient. Results Adjusting for age, gender, and smoking, a higher symptom burden was associated with increased sinonasal inflammation as captured by the MLM (β=0.453, p<0.013). As expected due to the differences in scales, the LM and MLM scores were significantly different (p<0.011). No association between MLM and SNOT-22 scores was found. Conclusions The MLM is one of the first imaging-based scoring systems that correlates with sinonasal symptoms. Further development of this custom software, including full automation and validation in larger samples, may yield a biomarker with great utility for both treatment of patients and outcomes assessment in clinical trials.

2c Laryngoscope, 1842-1850, 2018.

Background Traditional methods of staging chronic rhinosinusitis (CRS) through imaging do not differentiate between degrees of partial mucosal sinus inflammation, thus limiting their utility as imaging biomarkers. We hypothesized that software-aided, quantitative measurement of sinus inflammation would generate a metric of disease burden that would correlate with clinical parameters in patients with suspected sinus disease. Methods Adults with rhinologic complaints undergoing CT imaging were recruited at an urban, academic, tertiary care center (n=45 with Lund-Mackay [LM] scores ≥ 4). 3D volumetric image analysis was performed using a semi-automated method to obtain a “Chicago-modified Lund-Mackay” (Chicago MLM) score, which provides a continuous scale to quantify extent of opacification. Linear regression was used to test the association of the Chicago MLM score with concurrent symptoms (total nasal symptom scores [TNSS]) and disease-specific quality of life (Sinonasal Outcome Test-22 [SNOT22]). Results Chicago MLM scores were significantly associated with both symptoms (p=0.037) and disease-specific quality of life (p=0.007). Inflammation in the ethmoid and sphenoid sinuses appeared to influence these associations. These findings were even more robust when analysis was limited to patients with more severe disease (LM>6). Conclusions The quantitative measurement of sinus inflammation by computer-aided 3D analysis correlates modestly with both symptoms and disease-specific quality of life. Posterior sinuses appear to have the greatest impact on these findings, potentially providing an anatomic target for clinicians to base therapy. The Chicago MLM score is a promising imaging biomarker for clinical and research use.