Pneumothorax Safety of Pleural-Depth-Trimmed Hookwires for Lung Nodule Localization

December 10, 2025 updated by: Guo-Zhi Wang, Chung Shan Medical University

Pneumothorax Risk and Pleural-Depth-Trimmed Hookwire: A Retrospective Cohort Study With Propensity Score Matching in Preoperative CT-Guided Lung Nodule Localization

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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

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 (Actual)

1072

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Taiwan
      • Taichung, Taiwan, 402306
        • Chung Shan Medical University Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

The final analysis cohort included 1,072 POCTGL procedures. The procedures resulted in 1,567 evaluable lung nodules after the initial exclusion.

Demographics: The median age was 55 years (IQR, 48-63). The cohort was predominantly women (74.6%) and nonsmokers (86.3%).

Lesion Characteristics: The median lesion size was 6.5 mm (IQR, 5.0-8.0) , with a median depth from the pleura of 19 mm (IQR, 10.0-30.0).

Procedure Type: Most procedures (90.3%) were for initial VATS , and the majority involved a single lesion (65.5%).

Description

Inclusion Criteria:

  • Consecutive series of patients who underwent Preoperative Computed Tomography-Guided Lung Nodule Localization (POCTGL) at our medical center between September 2015 and January 2022.
  • All included procedures were performed in patients who subsequently underwent Video-Assisted Thoracoscopic Surgery (VATS) lung resection on the same day.

Exclusion Criteria For the primary Generalized Estimating Equations (GEE) analysis:

  • Nodules localized after a pneumothorax event occurred (n=59) were excluded.

Exclusion Criteria For the Propensity Score Matching (PSM) analysis:

  • Nodules localized after a pneumothorax event (n=59).
  • Nodules that were not the first localized nodule during the POCTGL procedure (n=495).
  • Nodules associated with a previous ipsilateral VATS (n=16).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Hookwire-Localized
This group consists of lung nodules that were localized using the Pleural-Depth-Trimmed Hookwire (Hawkins II breast localization needles, pre-trimmed to exceed the nodule-to-pleura depth by 5 mm to10 mm) combined with dye tattoos. This approach was primarily used for target lesions located >30 mm from the pleura. In the PSM analysis, this group served as the intervention group (n=237).
Procedure: Preoperative CT-Guided Lung Nodule Localization with Pleural-Depth-Trimmed Hookwire (PDTH) Technique

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.
Non-Hookwire-Localized
This group consists of lung nodules localized using only the Patent Blue Vital Dye. This method was used for target lesions located within 20 mm of the pleura. In the PSM analysis, this group served as the comparison group (n=237).
Procedure: Preoperative CTGuided Lung Nodule Localization with Patent Blue Vital Dye (PBVD) Localization Technique

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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Iatrogenic Pneumothorax Rate
Time Frame: Immediately following the localization procedure, documented on the final confirmatory CT scan.
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.
Immediately following the localization procedure, documented on the final confirmatory CT scan.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Requirement for Catheter Aspiration
Time Frame: Immediately post-localization, during the POCTGL procedure documentation.
The rate of procedures requiring therapeutic intervention (catheter aspiration) for severe pneumothorax, defined as an airspace thickness exceeding 3 cm.
Immediately post-localization, during the POCTGL procedure documentation.
Incidence of Other Adverse Events
Time Frame: Documented in real-time during the POCTGL procedure.
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.
Documented in real-time during the POCTGL procedure.
Technical Factors Associated with Pneumothorax
Time Frame: Assessed based on real-time procedural data collected during the POCTGL procedure.
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) .
Assessed based on real-time procedural data collected during the POCTGL procedure.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Chung Shan Medical University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 1, 2015

Primary Completion (Actual)

January 31, 2022

Study Completion (Actual)

January 31, 2022

Study Registration Dates

First Submitted

December 10, 2025

First Submitted That Met QC Criteria

December 10, 2025

First Posted (Actual)

December 23, 2025

Study Record Updates

Last Update Posted (Actual)

December 23, 2025

Last Update Submitted That Met QC Criteria

December 10, 2025

Last Verified

December 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • CS2-25160

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

The individual participant data (IPD) are not publicly available due to patient confidentiality and ethical restrictions. However, de-identified IPD supporting the findings of this study will be made available upon request. Researchers who meet the criteria for access to confidential data may submit requests to the Institutional Review Board (IRB) of Chung Shan Medical University Hospital, Taichung, Taiwan, for review and approval.

IPD Sharing Time Frame

Start Date: Upon request, 90 days after publication. End Date: Five years following study publication.

IPD Sharing Access Criteria

Access to the de-identified Individual Participant Data (IPD) and supporting documentation (e.g., Statistical Analysis Plan and Analytic Code ) will be considered for qualified researchers who meet the criteria for accessing confidential data.

Who: Qualified researchers who submit a detailed research proposal and sign a data access agreement.

What: De-identified IPD supporting the findings, along with the study protocol and statistical analytic code.

How: Requests must be submitted to the Institutional Review Board (IRB) of Chung Shan Medical University Hospital, Taichung, Taiwan, for formal review and approval. Access will be granted following a privacy risk assessment by the IRB and/or relevant institutional committees.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ANALYTIC_CODE

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Lung Nodules

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Czech Republic

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe