METHODS: The introduction of the surgical microscope into the neurosurgical field undoubtedly played an important and pivotal role in improving the surgical results and increasing the safety of operations in and around the third ventricle. Although the surgical microscope remained the gold standard of intraoperative visualization for many decades, the advent of endoscopes revolutionized surgery of the third ventricle. Neuroendoscopic procedures for lesions of the third ventricle encompass a greatly variable array of endochannel, endoscope-assisted and endoscope-controlled techniques.

METHODS: A 3-phase approach was undertaken: Phase 1: development of the weighted scoring system; Phase 2: estimating positive predicting value of MARK's Quadrant; and Phase 3: a) testing the validity of MARK's Quadrant in an open-access endoscope system; and b) comparing its usefulness compared to conventional referral system.

RESULTS: In phases 1 and 2, MARK's Quadrant with weighted symptoms was developed. The sensitivity of MARK's Quadrant is 88% and the specificity is 45.5% to detect cancerous and precancerous lesions of gastric. This was confirmed by the prospective data from phase 3 of this study where the diagnostic yield of MARK's Quadrant to detect any pathological lesion was 95.2%. This score has a high accuracy efficiency of 75%, hence comparing to routine referral system it has an odds ratio (95%CI) of 10.98 (4.63-26.00), 6.71 (4.46-10.09) and 0.95 (0.06-0.15) (P<0.001 respectively) for cancer, precancerous lesion and benign lesion diagnosis respectively.

METHODOLOGY: This is a descriptive cross-sectional study at the Sleep Clinic, Department of Otorhinolaryngology-Head and Neck Surgery. Flexible nasopharyngolaryngoscopy was performed in seated erect and supine position. Retropalatal and retroglossal regions were continuously recorded during quiet breathing and Mueller's maneuver in both positions. Captured images were measured using Scion Image software and narrowing rate was calculated. Level of each site was classified based on Fujita classification and severity of obstruction using Sher scoring system for Mueller's maneuver.

RESULTS: A total of 59 patients participated in this study. Twenty-nine (49.2%) participants had type 1 (retropalatal) obstruction, 23 (38.9%) had type 2 (retropalatal and retroglossal), and seven (11.9%) in type 3 (retroglossal) obstruction. Fifty (84.7%) of the patients have severe obstruction at the retropalatal region in supine position (SRP) followed by 35 (59.3%) at retropalatal region in erect position (ERP), 27 (45.8%) at retroglossal region in supine position (SRG) and eight (13.5%) at retroglossal region in erect position (ERG). The average oxygen saturation showed significant association in ERP (P = 0.012) and SRP (P < 0.001), but not significant in ERG and SRG.

METHODS: The MS of 5 fresh-frozen cadavers were sequentially dissected. Irrigation was evaluated with a squeeze bottle (SB) in different head positions and using different volumes of fluid. Surgical reach and visualization were examined using common sinus instruments and different angled endoscopes. A disease simulation was also performed to check for residual debris after instrumentation and irrigations.

RESULTS: Irrigation penetration improved as antrostomy size increased (p < 0.0001), with a significant difference observed between the extended procedures and MMA. The effect of the volume was significant for SB (p < 0.0001) but head positions appeared irrelevant (p = 0.613). Overall visualization improved for Mega-A and EMMA. A similar trend was seen for the reach of the instruments to all sinus wall subsites. EMMA facilitated the most removal of "sinus disease" in the disease simulation model when compared with both MMA and Mega-A, due to its reach of the anteroinferior aspects of the maxillary sinus.