The goal of this observational study is to learn about the pneumothorax risk associated with the Pleural-Depth-Trimmed Hookwire (PDTH) technique in patients undergoing Preoperative CT-Guided Lung Nodule Localization (POCTGL). The main question it aims to answer is: Does the specialized PDTH technique increase the risk of iatrogenic pneumothorax compared to dye-only localization in a setting utilizing advanced puncture guidance?. Participants were a retrospective cohort of patients who underwent POCTGL procedures between 2015 and 2022, and their procedural data and post-procedural complications were analyzed.
The unique contribution of this retrospective cohort study lies in its rigorous evaluation of an institutional, multi-component protocol for Preoperative CT-Guided Lung Nodule Localization (POCTGL), specifically focusing on the safety of the Pleural-Depth-Trimmed Hookwire (PDTH) technique when used in conjunction with the Laser Angle Guide Assembly (LAGA) system. Specialized Intervention Technique Pleural-Depth-Trimmed Hookwire (PDTH) Technical Rationale: The PDTH technique was developed to mitigate the high pneumothorax risk (historically reported up to 35%) associated with standard hookwires. This risk is hypothesized to result from the excessive length of the traditional hookwire protruding from the chest wall, causing friction and pleural trauma during patient movement and respiration. Execution: The standard localization hookwire (Hawkins II) is pre-trimmed prior to insertion. Its length is adjusted to only exceed the measured distance from the pleural surface to the target nodule by a minimal margin (5 mm∼10 mm), effectively eliminating the long, protruding segment. Combined Approach: For deep lesions (typically \>30 mm from the pleura), the PDTH is used in combination with a dual patent blue vital dye (PBV) tattooing strategy, providing multiple locational markers for the subsequent Video-Assisted Thoracoscopic Surgery (VATS). Laser Angle Guide Assembly (LAGA) The protocol incorporates the LAGA system, a device that provides visual, objective guidance for the needle trajectory. This system's primary benefit is to improve the accuracy of the initial puncture, which directly correlates with reducing the number of puncture attempts, a critical modifiable risk factor for pneumothorax confirmed by this study. Rigorous Statistical Methodology To provide a robust comparison despite the non-randomized, observational nature of the data, the study employed advanced statistical methods: Generalized Estimating Equations (GEE): Used to identify independent risk factors for pneumothorax across the entire cohort. GEE was crucial for accounting for the non-independence of observations, as many patients underwent multiple procedures or had multiple nodules localized within a single session. Propensity Score Matching (PSM): Utilized to control for selection bias inherent in marker choice (PDTH vs. dye-only). PSM was performed strictly on the first-localized nodule from each procedure, employing a 1:1 nearest-neighbor match, adjusted for key confounding variables like lobe location and specific patient position. Clinical Implications The study reports an overall iatrogenic pneumothorax rate of 5.6%, which is substantially lower than historical data, supporting the efficacy of the comprehensive protocol. Crucially, both GEE and PSM analyses confirmed that the use of the PDTH technique was not associated with an increased risk of pneumothorax compared to the dye-only localization group (PSM comparison: p=0.662), validating the specialized, modified hookwire technique as a safe option within this low-risk protocol.
Study Type
OBSERVATIONAL
Enrollment
1,072
The PDTH Technique is a modified localization method using the U.S. FDA-regulated Hawkins II hookwire (Argon Medical Devices, US). The standard wire is pre-trimmed to only exceed the nodule-to-pleura depth by a minimal 5 mm to 10 mm. This crucial modification aims to reduce iatrogenic pneumothorax risk by preventing excessive wire length from protruding and causing pleural friction or trauma during the procedure. This technique is primarily used for deeper lesions (\>30 mm from the pleura) and is integrated with the Laser Angle Guide Assembly (LAGA) system to ensure precise needle insertion and a dual patent blue vital dye tattooing strategy.
This intervention serves as the comparison group for the Pleural-Depth-Trimmed Hookwire (PDTH) technique in the Propensity Score Matching (PSM) analysis. This localization method utilizes only a vital dye marker and is generally associated with a lower complication risk due to its non-solid nature. Localization Marker: Patent blue vital dye (PBVD; Guerbet, France, 2.5%). Indication: The dye-only method was typically used for target lesions located within 20 mm of the pleura. Procedure: Two dye tattoos were marked on the lung parenchyma using a thinner 23-gauge, 89 mm spinal needle or a 23-gauge, 70 mm spinal needle. Guidance: Procedures were conducted under CT guidance, utilizing the Laser Angle Guide Assembly (LAGA) system. Purpose: In the context of this study, this group provides the benchmark comparison to determine the non-inferiority of the PDTH technique regarding the risk of iatrogenic pneumothorax.
Chung Shan Medical University Hospital
Taichung, Taiwan
Iatrogenic Pneumothorax Rate
The primary outcome is the incidence of iatrogenic pneumothorax documented as air presence on post-localization Computed Tomography (CT) scans. Pneumothorax was considered significant if the airspace thickness exceeded 3 cm. The rate was assessed to identify independent risk factors and to compare the safety of the Pleural-Depth-Trimmed Hookwire (PDTH) technique against non-hookwire localization.
Time frame: Immediately following the localization procedure, documented on the final confirmatory CT scan.
Requirement for Catheter Aspiration
The rate of procedures requiring therapeutic intervention (catheter aspiration) for severe pneumothorax, defined as an airspace thickness exceeding 3 cm.
Time frame: Immediately post-localization, during the POCTGL procedure documentation.
Incidence of Other Adverse Events
The incidence rate of other documented complications at the time of the POCTGL procedures. These complications included intolerable pain, severe cough, dizziness, and hookwire dislodgement.
Time frame: Documented in real-time during the POCTGL procedure.
Technical Factors Associated with Pneumothorax
Identifying independent risk factors (e.g., number of puncture attempts, lesion order, patient position) associated with increased odds of pneumothorax using Generalized Estimating Equations (GEE) .
Time frame: Assessed based on real-time procedural data collected during the POCTGL procedure.
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