Factors Affecting Accuracy And Efficacy Of Intraoperative Localization Of Small Peripheral GGN With Electromagnatic Navigation Bronchoscopy
Kwanyong Hyun, In Kyu Park, Young Tae Kim, Samina Park.
Seoul National University Hospital, Seoul, Korea, Republic of.
OBJECTIVE: Electromagnetic navigational bronchoscopy (ENB)-guided dye marking is a novel method to localize peripheral ground glass nodules (GGNs). This method is being used with increasing frequency, which makes the accurate target planning important for effective navigation. We investigated factors affecting the accuracy and efficacy of targeting. METHODS: Patients with sub-centimeter GGN who underwent ENB-guided marking and VATS resection from July 2016 to August 2017 were reviewed retrospectively. Marking target was set at the nearest pleura from the GGN. Data were captured during navigational planning and routing and this included location of the target, target angle from navigation pathway, distance between target and navigation tip (target distance), distance between target and the bronchial exit point (tunnelling distance), the time spent for navigation (navigation time) and lastly, engagement failure to the planned route. For the study purpose, locations of GGN were categorized as 3 groups according to the bronchial structure; the upper zone (LUL upper division and RUL), the middle zone (RML, lingular and superior segments), and the lower zone (basal segments). Target angle was obtained as a maximal angle at either axial, coronal or sagittal planning map. All these data were submitted to linear regression analysis. RESULTS: A total of 29 ENB-guided markings were performed in 20 patients. Dye-marker was not visible in 1 nodules (6.9%), but all 24 GGNs were completely resected with the use of manual palpation. The location of targets were 9 in upper zone, 14 in middle zone, and 6 in lower zone. While the target-distance showed no significant inter-zone difference, the navigation-time was longer in upper zone (upper vs middle/lower, 9.0±8.5 min vs 5.3±3.0 min, p=0.19). Multiple linear regression analyses were performed to identify the impact of variables on planning accuracy (target distance) and efficacy (navigation time). Target angle (ß=0.013, t=3.8, p=0.0008) and engagement failure (ß=0.80, t=2.0, p=0.032) were identified as significant predictors of planning accuracy. On the other hand, tunneling distance (ß=2.41, t=3.0, p=0.024) and engagement failure (ß=6.11, t=3.6, p=0.005) contributed significantly to the predictive value of planning efficacy. CONCLUSIONS: Engagement failure was related to the planning efficacy and accuracy simultaneously. Planning accuracy was more influenced by acute target angle and planning efficacy was affected more by tunneling distance. More experience of target setting and selection of catheter-angle are necessary to enhance the efficacy and accuracy of ENB-guided dye marking. 
Back to 2018 ePosters